Host cities:
| Athlete | Nation(s) | Sport(s) | Role(s) | Era | Notes | 
|---|---|---|---|---|---|
| Brooke Abel |  USA | SWA | Olympics | 2008 | 0–0–1 2007 Melbourne SYN bronze: team Free Routine Combination | 
| Jennifer Abel |  CAN | DIV | Olympics | 2008—2020 | 0–6–4 2011 Shanghai DIV silver: synchronized springboard, bronze: 3 m springboard; 2013 Barcelona DIV bronze: synchronized springboard; 2015 Kazan DIV silver: synchronized springboard and synchronized springboard (mixed); 2017 Budapest DIV silver: synchronized springboard, bronze: 3 m springboard and synchronized springboard (mixed); 2019 Gwangju DIV silver: synchronized springboard and synchronized springboard (mixed) | 
| Viktor Aboimov |  KAZ  URS | SWM | Olympics | 1972 | 0–1–1 1973 Belgrade SWI silver: 4×100 m freestyle relay; 1975 Cali SWI bronze: 4×200 m freestyle relay | 
| Matt Abood |  AUS | SWM | Olympics | 2016 | 1–0–0 2011 Shanghai SWI gold: 4×100 m freestyle relay | 
| Gary Abraham |  GBR | SWM | Olympics | 1976—1980 | 0–0–1 1978 West Berlin SWI bronze: 4×100 m medley relay | 
| Inna Abramova |  RUS  URS | SWM | Olympics | 1988 | 0–0–1 1982 Guayaquil SWI bronze: 4×100 m medley relay (swam in heats only) | 
| Irina Abysova |  RUS | TRI | Olympics | 2008—2012 | 0–1–0 2001 Fukuoka SWI silver: 10 km open water | 
| Javier Acevedo |  CAN | SWM | Olympics / YOG | 2014—2020 | 0–0–2 2017 Budapest SWI bronze: 4×100 m freestyle mixed relay and 4×100 m medley mixed relay (swam in heats only) | 
| Yumi Adachi |  JPN | SWA | Olympics | 2012 | 0–0–2 2019 Gwangju SYN bronze: duet Technical (mixed) and duet Free (mixed) | 
| Cammile Adams |  USA | SWM | Olympics | 2012—2016 | 0–1–0 2015 Kazan SWI silver: 200 m butterfly | 
| Beatrice Adelizzi |  ITA | SWA | Olympics | 2008 | 0–0–1 2009 Roma SYN bronze: solo Free | 
| Becky Adlington |  GBR | SWM | Olympics | 2008—2012 | 1–1–2 2009 Roma SWI bronze: 400 m freestyle and 4×200 m freestyle relay; 2011 Shanghai SWI gold: 800 m freestyle, silver: 400 m freestyle | 
| Nathan Adrian |  USA | SWM | Olympics | 2008—2016 | 10–4–2 2009 Roma SWI gold: 4×100 m freestyle relay and 4×100 m medley relay (swam in heats only); 2011 Shanghai SWI gold: 4×100 m medley relay, bronze: 4×100 m freestyle relay; 2013 Barcelona SWI silver: 4×100 m freestyle relay, bronze: 100 m freestyle; 2015 Kazan SWI gold: 4×100 m medley relay and 4×100 m freestyle mixed relay, silver: 50 m freestyle; 2017 Budapest SWI gold: 4×100 m freestyle relay, 4×100 m medley relay, and 4×100 m freestyle mixed relay, silver: 100 m freestyle; 2019 Gwangju SWI gold: 4×100 m freestyle relay and 4×100 m freestyle mixed relay (swam in heats only), silver: 4×100 m medley relay | 
| Christos Afroudakis |  GRE | WPO | Olympics | 2004—2016 | 0–0–2 2005 Montréal WAP bronze; 2015 Kazan WAP bronze | 
| Georgios Afroudakis |  GRE | WPO | Olympics | 1996—2012 | 0–0–1 2005 Montréal WAP bronze | 
| Yannick Agnel |  FRA | SWM | Olympics | 2012—2016 | 2–1–0 2011 Shanghai SWI silver: 4×200 m freestyle relay; 2013 Barcelona SWI gold: 200 m freestyle and 4×100 m freestyle relay | 
| Iñaki Aguilar |  ESP | WPO | Olympics | 2008—2016 | 0–1–1 2007 Melbourne WAP bronze; 2009 Roma WAP silver | 
| Jeinkler Aguirre |  CUB | DIV | Olympics | 2008—2012 | 0–0–1 2009 Roma DIV bronze: synchronized platform | 
| Crissy Ahmann-Leighton |  USA | SWM | Olympics | 1992 | 1–0–0 1991 Perth SWI gold: 4×100 m medley relay | 
| Ai Yanhan |  CHN | SWM | Olympics | 2016—2020 | 0–1–0 2017 Budapest SWI silver: 4×200 m freestyle relay | 
| Matteo Aicardi |  ITA | WPO | Olympics | 2012—2020 | 2–0–0 2011 Shanghai WAP gold; 2019 Gwangju WAP gold | 
| Rosaria Aiello |  ITA | WPO | Olympics | 2016 | 0–0–1 2015 Kazan WAP bronze | 
| Aleksey Akatyev |  RUS | SWM | Olympics | 1996 | 2–1–1 1994 Roma SWI bronze: 25 km open water; 1998 Perth SWI gold: 5 km open water and 25 km open water, silver: 5 km open water team | 
| Anatoly Akimov |  RUS  URS | WPO | Olympics | 1972 | 0–1–0 1973 Belgrade WAP silver | 
| Vladimir Akimov |  RUS  URS | WPO | Olympics | 1980 | 1–0–0 1982 Guayaquil WAP gold | 
| Irina Aksyonova |  RUS  URS | SWM | Olympics | 1980 | 0–0–1 1978 West Berlin SWI bronze: 4×100 m medley relay | 
| Alberto Alberani Samaritani |  ITA | WPO | Olympics | 1968—1980 | 1–0–1 1975 Cali WAP bronze; 1978 West Berlin WAP gold | 
| María José Alcalá |  MEX | DIV | Olympics / Administrator | 1988—2021 | 0–0–1 1994 Roma DIV bronze: platform | 
| Vadim Alekseyev |  ISR  KAZ  URS | SWM | Olympics | 1988—1996 | 0–1–0 1991 Perth SWI silver: 4×100 m medley relay (swam in heats only) (competed for the Soviet Union) | 
| Milan Aleksić |  SRB | WPO | Olympics | 2012—2020 | 2–1–1 2009 Roma WAP gold; 2011 Shanghai WAP silver; 2015 Kazan WAP gold; 2017 Budapest WAP bronze | 
| Lisa Alexander |  CAN | SWA | Olympics | 1996 | 0–3–3 1991 Perth SYN silver: team, bronze: duet; 1994 Roma SYN silver: duet and team, bronze: solo; 2001 Fukuoka SYN bronze: team | 
| Vladimir Aleynik |  BLR  URS | DIV | Olympics | 1976—1980 | 0–1–1 1978 West Berlin DIV bronze: platform; 1982 Guayaquil DIV silver: platform | 
| Carmela Allucci |  ITA | WPO | Olympics / Other | 2004 | 2–1–0 1998 Perth WAP gold; 2001 Fukuoka WAP gold; 2003 Barcelona WAP silver | 
| Franziska van Almsick |  GER | SWM | Olympics | 1992—2004 | 2–2–2 1994 Roma SWI gold: 200 m freestyle, silver: 4×200 m freestyle relay, bronze: 100 m freestyle and 4×100 m freestyle relay; 1998 Perth SWI gold: 4×200 m freestyle relay, silver: 4×100 m freestyle relay | 
| Therèse Alshammar |  SWE | SWM | Olympics / Other | 1996—2016 | 2–5–1 2001 Fukuoka SWI silver: 50 m freestyle and 50 m butterfly, bronze: 50 m butterfly; 2007 Melbourne SWI gold: 50 m butterfly, silver: 50 m freestyle; 2009 Roma SWI silver: 50 m freestyle; 2011 Shanghai SWI gold: 50 m freestyle, silver: 50 m butterfly | 
| Yevgeny Alyoshin |  RUS | SWM | Olympics | 2004 | 0–1–0 2003 Barcelona SWI silver: 4×100 m medley relay (swam in heats only) | 
| Vladislav Aminov |  RUS | SWM | Olympics | 2000 | 0–0–1 2001 Fukuoka SWI bronze: 4×100 m medley relay | 
| Gail Amundrud |  CAN | SWM | Olympics | 1976 | 0–0–2 1975 Cali SWI bronze: 4×100 m freestyle relay; 1978 West Berlin SWI bronze: 4×100 m freestyle relay | 
| Lolita Ananasova |  UKR | SWA | Olympics | 2016 | 0–0–4 2013 Barcelona SYN bronze: team Technical, team Free, and team Free Routine Combination; 2015 Kazan SYN bronze: duet Free | 
| Alyssa Anderson |  USA | SWM | Olympics | 2012 | 0–1–0 2009 Roma SWI silver: 4×200 m freestyle relay (swam in heats only) | 
| Haley Anderson |  USA | OWS | Olympics | 2012—2020 | 2–2–1 2013 Barcelona SWI gold: 5 km open water; 2015 Kazan SWI gold: 5 km open water; 2017 Budapest SWI silver: 4×1.25 km open water relay; 2019 Gwangju SWI silver: 10 km open water, bronze: 4×1.25 km open water relay | 
| Jakob Andkjær |  DEN | SWM | Olympics | 2008 | 0–0–1 2007 Melbourne SWI bronze: 50 m butterfly | 
| Ángel Luis Andreo |  ESP | WPO | Olympics / Non-starter | 1996—2008 | 1–0–1 2001 Fukuoka WAP gold; 2007 Melbourne WAP bronze | 
| Alberto Angelini |  ITA | WPO | Olympics | 1996—2008 | 0–1–0 2003 Barcelona WAP silver | 
| Hannelore Anke |  GDR | SWM | Olympics | 1972—1976 | 3–1–0 1973 Belgrade SWI silver: 200 m breaststroke; 1975 Cali SWI gold: 100 m breaststroke, 200 m breaststroke, and 4×100 m medley relay | 
| Dóra Antal |  HUN | WPO | Olympics | 2012—2016 | 0–0–1 2013 Barcelona WAP bronze | 
| Stavroula Antonakou |  GRE | WPO | Olympics | 2008 | 1–0–0 2011 Shanghai WAP gold | 
| Aleksandra Antonova |  RUS | WPO | Olympics | 2012 | 0–0–1 2011 Shanghai WAP bronze | 
| Ai Aoki |  JPN | SWA | Olympics | 2008 | 0–1–0 2007 Melbourne SYN silver: team Free Routine Combination | 
| Mayumi Aoki |  JPN | SWM | Olympics | 1972 | 0–0–1 1973 Belgrade SWI bronze: 100 m butterfly | 
| Ayari Aoyama |  JPN | SWM | Olympics | 1996 | 0–1–1 1998 Perth SWI silver: 100 m butterfly, bronze: 4×100 m medley relay | 
| Dmitry Apanasenko |  RUS  URS  EUN | WPO | Olympics | 1988—1996 | 0–0–2 1986 Madrid WAP bronze (competed for the Soviet Union); 1994 Roma WAP bronze (competed for Russia) | 
| Zoe Arancini |  AUS | WPO | Olympics | 2016—2020 | 0–1–1 2013 Barcelona WAP silver; 2019 Gwangju WAP bronze | 
| Rômulo Arantes |  BRA | SWM | Olympics | 1972—1980 | 0–0–1 1978 West Berlin SWI bronze: 100 m backstroke | 
| Kelly Araouzou |  GRE | OWS | Olympics | 2016 | 0–2–0 2013 Barcelona SWI silver: 5 km open water team; 2015 Kazan SWI silver: 5 km open water | 
| Alexandra Araujo |  ITA | WPO | Olympics | 2004 | 2–1–0 1998 Perth WAP gold (competed for Italy); 2001 Fukuoka WAP gold (competed for Italy); 2003 Barcelona WAP silver (competed for Italy) | 
| Samantha Arévalo |  ECU | OWS/SWM | Olympics | 2012—2020 | 0–1–0 2017 Budapest SWI silver: 10 km | 
| Marie-Thérèse Armentero |  SUI | SWM | Olympics | 1984—1988 | 0–0–1 1986 Madrid SWI bronze: 50 m freestyle | 
| Betsey Armstrong |  USA | WPO | Olympics | 2008—2012 | 2–0–0 2007 Melbourne WAP gold; 2009 Roma WAP gold | 
| Örn Arnarson |  ISL | SWM | Olympics / Other | 2000—2008 | 0–1–1 2001 Fukuoka SWI silver: 100 m backstroke, bronze: 200 m backstroke | 
| Marie-Luc Arpin |  CAN | WPO | Olympics | 2000—2004 | 0–0–2 2001 Fukuoka WAP bronze; 2005 Montréal WAP bronze | 
| Pär Arvidsson |  SWE | SWM | Olympics | 1976—1980 | 0–0–1 1978 West Berlin SWI bronze: 100 m butterfly | 
| Jessica Ashwood |  AUS | SWM | Olympics | 2012—2016 | 0–0–1 2015 Kazan SWI bronze: 400 m freestyle | 
| Alexandra Asimaki |  GRE | WPO | Olympics | 2008 | 1–0–0 2011 Shanghai WAP gold | 
| Alia Atkinson |  JAM | SWM | Olympics | 2004—2020 | 0–1–1 2015 Kazan SWI silver: 50 m breaststroke, bronze: 100 m breaststroke | 
| Francesco Attolico |  ITA | WPO | Olympics | 1992—2000 | 1–0–0 1994 Roma WAP gold | 
| Isabelle Auger |  CAN | WPO | Olympics | 2000 | 0–1–0 1991 Perth WAP silver | 
| Gianni Averaimo |  ITA | WPO | Olympics / Non-starter | 1988—1992 | 1–1–0 1986 Madrid WAP silver; 1994 Roma WAP gold | 
| Yelena Azarova |  RUS | SWA | Olympics | 1996—2004 | 1–0–0 1998 Perth SYN gold: team | 
| Jack Babashoff |  USA | SWM | Olympics | 1976 | 1–0–0 1978 West Berlin SWI gold: 4×100 m freestyle relay | 
| Shirley Babashoff |  USA | SWM | Olympics | 1972—1976 | 2–7–1 1973 Belgrade SWI silver: 100 m freestyle, 200 m freestyle, 4×100 m freestyle relay, and 4×100 m medley relay; 1975 Cali SWI gold: 200 m freestyle and 400 m freestyle, silver: 100 m freestyle, 4×100 m freestyle relay, and 4×100 m medley relay, bronze: 800 m freestyle | 
| Kristen Babb-Sprague |  USA | SWA | Olympics | 1992 | 1–2–0 1986 Madrid SYN silver: team (competed as Kristen Babb); 1991 Perth SYN gold: team, silver: solo (competed as Kristen Babb) | 
| Marina Babkova |  RUS  URS | DIV | Olympics | 1988 | 0–0–1 1986 Madrid DIV bronze: 3 m springboard | 
| Marta Bach |  ESP | WPO | Olympics | 2012—2020 | 1–2–0 2013 Barcelona WAP gold; 2017 Budapest WAP silver; 2019 Gwangju WAP silver | 
| Robin Backhaus |  USA | SWM | Olympics | 1972 | 4–0–1 1973 Belgrade SWI gold: 200 m Butterfly. 4×200 m freestyle relay. and 4×100 m medley relay (swam in heats only), bronze: 100 m butterfly; 1975 Cali SWI gold: 4×100 m freestyle relay (swam in heats only) | 
| Steve Badger |  CAN | SWM | Olympics | 1976 | 0–1–0 1973 Belgrade SWI silver: 4×200 m freestyle relay (competed for Australia) | 
| Angie Bainbridge |  AUS | SWM | Olympics | 2008—2012 | 0–1–0 2011 Shanghai SWI silver: 4×200 m freestyle relay | 
| Kathleen Baker |  USA | SWM | Olympics | 2016 | 1–1–1 2017 Budapest SWI gold: 4×100 m medley relay, silver: 100 m backstroke, bronze: 200 m backstroke | 
| Roman Balashov |  RUS | WPO | Olympics | 2000—2004 | 0–0–1 2001 Fukuoka WAP bronze | 
| Brita Baldus |  GDR  GER | DIV | Olympics | 1988—1992 | 0–0–1 1991 Perth DIV bronze: 3 m springboard (competed for Germany) | 
| Kirsty Balfour |  GBR | SWM | Olympics | 2004—2008 | 0–1–0 2007 Melbourne SWI silver: 200 m breaststroke | 
| Daniel Ballart |  ESP | WPO | Olympics | 1992—2004 | 2–2–0 1991 Perth WAP silver; 1994 Roma WAP silver; 1998 Perth WAP gold; 2001 Fukuoka WAP gold | 
| Coralie Balmy |  FRA | SWM | Olympics | 2008—2016 | 0–0–1 2013 Barcelona SWI bronze: 4×200 m freestyle relay | 
| Frank Baltrusch |  GDR | SWM | Olympics | 1988 | 0–1–1 1982 Guayaquil SWI bronze: 200 m backstroke; 1986 Madrid SWI silver: 200 m backstroke | 
| Samir Barać |  CRO | WPO | Olympics | 2000—2012 | 1–0–2 2007 Melbourne WAP gold; 2009 Roma WAP bronze; 2011 Shanghai WAP bronze | 
| Silvio Baracchini |  ITA | WPO | Olympics | 1972—1976 | 1–0–1 1975 Cali WAP bronze; 1978 West Berlin WAP gold | 
| Paolo Barelli |  ITA | SWM | Olympics | 1972—1976 | 0–0–1 1975 Cali SWI bronze: 4×100 m freestyle relay | 
| Aleksey Barkalov |  URS  UKR | WPO | Olympics | 1968—1980 | 1–1–0 1973 Belgrade WAP silver; 1975 Cali WAP gold | 
| Romain Barnier |  FRA | SWM | Olympics | 2000—2004 | 0–0–1 2003 Barcelona SWI bronze: 4×100 m freestyle relay | 
| Bengt Baron |  SWE | SWM | Olympics | 1980—1984 | 0–0–2 1982 Guayaquil SWI bronze: 100 m butterfly and 4×100 m freestyle relay | 
| Bronte Barratt |  AUS | SWM | Olympics | 2008—2016 | 1–3–0 2005 Montréal SWI silver: 4×200 m freestyle relay; 2011 Shanghai SWI silver: 4×200 m freestyle relay; 2013 Barcelona SWI silver: 4×200 m freestyle relay; 2015 Kazan SWI gold: 4×100 m freestyle relay (swam in heats only) | 
| Mike Barrowman |  USA | SWM | Olympics | 1988—1992 | 2–0–0 1991 Perth SWI gold: 200 m breaststroke and 4×100 m medley relay (swam in heats only) | 
| Carrie Barton |  USA | SWA | Olympics | 2000 | 0–0–1 1998 Perth SYN bronze: team | 
| Alison Bartosik |  USA | SWA | Olympics | 2004 | 0–1–1 2003 Barcelona SYN silver: team Free Routine Combination, bronze: team | 
| Heidemarie Bártová-Grécká |  CZE  TCH | DIV | Olympics | 1980—1992 | 0–0–1 1991 Perth DIV bronze: 1 m springboard | 
| Iurie Bașcatov |  MDA  URS  EUN | SWM | Olympics | 1988—1992 | 0–1–1 1991 Perth SWI silver: 4×100 m medley relay (swam in heats only), bronze: 4×100 m freestyle relay (competed for the Soviet Union) | 
| Clara Basiana |  ESP | SWA | Olympics | 2012 | 0–3–2 2011 Shanghai SYN bronze: team Technical and team Free; 2013 Barcelona SYN silver: team Technical, team Free, and team Free Routine Combination | 
| Stefano Battistelli |  ITA | SWM | Olympics | 1988—1992 | 0–2–2 1986 Madrid SWI silver: 1500 m freestyle; 1991 Perth SWI silver: 200 m backstroke, bronze: 400 m medley and 4×200 m freestyle relay | 
| Alex Baumann |  CAN | SWM | Olympics / Other | 1984 | 0–1–1 1986 Madrid SWI silver: 200 m medley, bronze: 400 m medley | 
| Nadezhda Bazhina |  RUS | DIV | Olympics | 2012—2016 | 0–1–1 2017 Budapest DIV silver: 1 m springboard, bronze: synchronized springboard | 
| Gemma Beadsworth |  AUS | WPO | Olympics | 2008—2016 | 0–1–0 2007 Melbourne WAP silver | 
| Amanda Beard |  USA | SWM | Olympics | 1996—2008 | 1–2–0 2003 Barcelona SWI gold: 200 m breaststroke, silver: 100 m breaststroke and 4×100 m medley relay | 
| Robin Beauregard |  USA | WPO | Olympics | 2000—2004 | 1–0–0 2003 Barcelona WAP gold | 
| Andrea Beccari |  ITA | SWM | Olympics | 2000—2004 | 0–1–0 2001 Fukuoka SWI silver: 4×200 m freestyle relay | 
| Leonie Beck |  GER | OWS/SWM | Olympics | 2016—2020 | 0–0–1 2019 Gwangju SWI bronze: 5 km open water | 
| Reinhold Becker |  FRG | SWM | Olympics | 1976 | 0–1–0 1978 West Berlin SWI silver: 4×100 m medley relay (swam in heats only) | 
| Gudrun Beckmann |  FRG | SWM | Olympics | 1972—1976 | 0–0–2 1973 Belgrade SWI bronze: 4×100 m freestyle relay and 4×100 m medley relay | 
| Brigitte Becue |  BEL | SWM | Olympics | 1988—2000 | 0–0–1 1994 Roma SWI bronze: 200 m breaststroke | 
| B. J. Bedford |  USA | SWM | Olympics | 2000 | 2–0–1 1994 Roma SWI bronze: 100 m backstroke; 1998 Perth SWI gold: 4×100 m freestyle relay and 4×100 m medley relay (swam in heats only) | 
| Domonic Bedggood |  AUS | DIV | Olympics | 2016 | 0–0–1 2015 Kazan DIV bronze: synchronized platform (mixed) | 
| Johanne Bégin |  CAN | WPO | Olympics | 2000—2004 | 0–0–2 2001 Fukuoka WAP bronze; 2005 Montréal WAP bronze | 
| Roswitha Beier |  GDR | SWM | Olympics | 1972 | 0–1–0 1973 Belgrade SWI silver: 200 m butterfly | 
| Elizabeth Beisel |  USA | SWM | Olympics | 2008—2016 | 1–0–2 2009 Roma SWI bronze: 200 m backstroke; 2011 Shanghai SWI gold: 400 m medley; 2013 Barcelona SWI bronze: 400 m medley | 
| Mireia Belmonte |  ESP | SWM | Olympics / Other | 2008—2020 | 1–4–1 2013 Barcelona SWI silver: 200 m butterfly and 400 m medley, bronze: 200 m medley; 2017 Budapest SWI gold: 200 m butterfly, silver: 1500 m freestyle and 400 m medley | 
| Melissa Belote |  USA | SWM | Olympics | 1972—1976 | 1–2–0 1973 Belgrade SWI gold: 200 m backstroke, silver: 100 m backstroke and 4×100 m medley relay | 
| Olga Belova-Gorbunova |  RUS | WPO | Olympics | 2012—2016 | 0–0–1 2017 Budapest WAP bronze (competed as Olga Gorbunova) | 
| Janine Belton |  GBR | SWM | Olympics | 1996—2000 | 1–0–0 2001 Fukuoka SWI gold: 4×200 m freestyle relay | 
| Olga Belyayeva |  RUS | WPO | Olympics | 2008—2012 | 0–0–2 2009 Roma WAP bronze; 2011 Shanghai WAP bronze | 
| Fabio Bencivenga |  ITA | WPO | Olympics | 1996—2008 | 0–1–0 2003 Barcelona WAP silver | 
| Tibor Benedek |  HUN | WPO | Olympics / Coach | 1992—2016 | 1–2–1 1991 Perth WAP bronze; 1998 Perth WAP silver; 2003 Barcelona WAP gold; 2007 Melbourne WAP silver | 
| Meaghan Benfeito |  CAN | DIV | Olympics | 2008—2020 | 0–3–1 2005 Montréal DIV bronze: synchronized platform; 2013 Barcelona DIV silver: synchronized platform; 2015 Kazan DIV silver: synchronized platform and synchronized platform (mixed) | 
| Lindsay Benko |  USA | SWM | Olympics | 2000—2004 | 2–2–0 1998 Perth SWI silver: 4×200 m freestyle relay; 2003 Barcelona SWI gold: 4×100 m freestyle relay and 4×200 m freestyle relay, silver: 4×100 m medley relay | 
| Brooke Bennett |  USA | SWM | Olympics | 1996—2000 | 1–2–1 1994 Roma SWI bronze: 800 m freestyle; 1998 Perth SWI gold: 800 m freestyle, silver: 400 m freestyle and 4×200 m freestyle relay | 
| Conny van Bentum |  NED | SWM | Olympics | 1980—1988 | 0–0–5 1982 Guayaquil SWI bronze: 4×100 m freestyle relay; 1986 Madrid SWI bronze: 100 m freestyle, 4×100 m freestyle relay, 4×200 m freestyle relay, and 4×100 m medley relay | 
| Viktor Berendyuga |  URS  UKR | WPO | Olympics | 1988 | 0–0–1 1986 Madrid WAP bronze | 
| Ricky Berens |  USA | SWM | Olympics | 2008—2012 | 4–1–0 2009 Roma SWI gold: 4×200 m freestyle relay and 4×100 m freestyle relay (swam in heats only); 2011 Shanghai SWI gold: 4×200 m freestyle relay; 2013 Barcelona SWI gold: 4×200 m freestyle relay, silver: 4×100 m freestyle relay (swam in heats only) | 
| Gillian van den Berg |  NED | WPO | Olympics | 2000—2008 | 0–2–0 1994 Roma WAP silver; 1998 Perth WAP silver | 
| Alain Bernard |  FRA | SWM | Olympics | 2008—2012 | 0–2–3 2007 Melbourne SWI bronze: 4×100 m freestyle relay; 2009 Roma SWI silver: 100 m freestyle, bronze: 4×100 m freestyle relay; 2011 Shanghai SWI silver: 4×100 m freestyle relay, bronze: 50 m freestyle | 
| Jens-Peter Berndt |  FRG | SWM | Olympics | 1988 | 0–1–0 1982 Guayaquil SWI silver: 400 m medley (competed for East Germany) | 
| Elena Bertocchi |  ITA | DIV | Olympics / YOG | 2010—2020 | 0–0–1 2017 Budapest DIV bronze: 1 m springboard | 
| Mislav Bezmalinović |  CRO  YUG | WPO | Olympics | 1988 | 1–0–0 1991 Perth WAP gold | 
| Suzannah Bianco |  USA | SWA | Olympics | 1996 | 1–0–0 1994 Roma SYN gold: team | 
| Roberta Bianconi |  ITA | WPO | Olympics | 2012—2016 | 0–0–1 2015 Kazan WAP bronze | 
| Paul Biedermann |  GER | SWM | Olympics | 2008—2016 | 2–1–4 2009 Roma SWI gold: 200 m freestyle and 400 m freestyle, silver: 4×100 m medley relay; 2011 Shanghai SWI bronze: 200 m freestyle, 400 m freestyle, and 4×100 m medley relay; 2015 Kazan SWI bronze: 200 m freestyle | 
| Marko Bijač |  CRO | WPO | Olympics | 2016—2020 | 1–1–2 2013 Barcelona WAP bronze; 2015 Kazan WAP silver; 2017 Budapest WAP gold; 2019 Gwangju WAP bronze | 
| Matt Biondi |  USA | SWM | Olympics | 1984—1992 | 6–2–3 1986 Madrid SWI gold: 100 m freestyle, 4×100 m freestyle relay, and 4×100 m medley relay, silver: 100 m butterfly, bronze: 50 m freestyle, 200 m freestyle, and bronze: 4×200 m freestyle relay; 1991 Perth SWI gold: 100 m freestyle, 4×100 m freestyle relay, and 4×100 m medley relay, silver: 50 m freestyle | 
| Péter Biros |  HUN | WPO | Olympics / Other | 2000—2012 | 1–2–0 2003 Barcelona WAP gold; 2005 Montréal WAP silver; 2007 Melbourne WAP silver | 
| Iso Bishop |  AUS | WPO | Olympics | 2016 | 0–1–1 2013 Barcelona WAP silver; 2019 Gwangju WAP bronze | 
| Andrea Blas |  ESP | WPO | Olympics | 2012 | 1–0–0 2013 Barcelona WAP gold | 
| Pernille Blume |  DEN | SWM | Olympics / Other | 2012—2020 | 0–0–1 2017 Budapest SWI bronze: 100 m freestyle | 
| Claudia Bockner |  GER | DIV | Olympics | 1996 | 0–0–1 1994 Roma DIV bronze: 3 m springboard | 
| Michaël Bodegas |  ITA | WPO | Olympics | 2016—2020 | 1–0–0 2019 Gwangju WAP gold | 
| András Bodnár |  HUN | SWM/WPO | Olympics | 1960—1972 | 1–1–0 1973 Belgrade WAP gold; 1975 Cali WAP silver | 
| Hellen Boering |  NED | WPO | Olympics | 2000 | 1–2–0 1986 Madrid WAP silver; 1991 Perth WAP gold; 1994 Roma WAP silver | 
| Andrey Bogdanov |  RUS  URS | SWM | Olympics | 1976 | 0–0–1 1975 Cali SWI bronze: 4×200 m freestyle relay (swam in heats only) | 
| Svetlana Bogdanova |  RUS | WPO | Olympics | 2004 | 0–0–1 2003 Barcelona WAP bronze | 
| Yuliya Bogdanova |  RUS  URS | SWM | Olympics | 1980 | 1–1–1 1978 West Berlin SWI gold: 100 m breaststroke, silver: 200 m breaststroke, bronze: 4×100 m medley relay | 
| Alessio Boggiatto |  ITA | SWM | Olympics | 2000—2008 | 1–0–0 2001 Fukuoka SWI gold: 400 m medley | 
| Phil Boggs |  USA | DIV | Olympics | 1976 | 3–0–0 1973 Belgrade DIV gold: 3 m springboard; 1975 Cali DIV gold: 3 m springboard; 1978 West Berlin DIV gold: 3 m springboard | 
| Tanya Bogomilova-Dangalakova |  BUL | SWM | Olympics | 1980—1988 | 0–1–1 1986 Madrid SWI silver: 200 m breaststroke, bronze: 100 m breaststroke (competed as Tanya Bogomilova) | 
| Richárd Bohus |  HUN | SWM | Olympics | 2012—2020 | 0–0–1 2017 Budapest SWI bronze: 4×100 m freestyle relay | 
| Flóra Bolonyai |  HUN | WPO | Olympics | 2012 | 0–0–1 2013 Barcelona WAP bronze | 
| Sergey Bolshakov |  RUS | OWS | Olympics | 2012 | 0–0–1 2011 Shanghai SWI bronze: 10 km open water | 
| Oleksandr Bondar |  ROC  UKR | DIV | Olympics / YOG | 2010—2020 | 0–2–2 2011 Shanghai DIV bronze: synchronized platform; 2017 Budapest DIV silver: synchronized platform (competed as Aleksandr Bondar for Russia); 2019 Gwangju DIV silver: synchronized platform, bronze: platform (competed as Aleksandr Bondar for Russia) | 
| Charlotte Bonnet |  FRA | SWM | Olympics | 2012—2020 | 0–0–2 2013 Barcelona SWI bronze: 4×200 m freestyle relay; 2019 Gwangju SWI bronze: 4×100 m freestyle mixed relay | 
| Gustavo Borges |  BRA | SWM | Olympics / Other | 1992—2004 | 0–0–2 1994 Roma SWI bronze: 100 m freestyle and 4×100 m freestyle relay | 
| Aleksey Borislavsky |  URS  UKR | SWM | Olympics | 1988 | 0–0–1 1991 Perth bronze: 4×100 m freestyle relay (swam in heats only) | 
| Mariya Borisova |  RUS | WPO | Olympics | 2016 | 0–0–1 2017 Budapest WAP bronze | 
| Miho Bošković |  CRO | WPO | Olympics | 2008—2012 | 1–0–2 2007 Melbourne WAP gold; 2009 Roma WAP bronze; 2011 Shanghai WAP bronze | 
| Silvia Bosurgi |  ITA | WPO | Olympics | 2004—2008 | 1–1–0 2001 Fukuoka WAP gold; 2003 Barcelona WAP silver | 
| Beth Botsford |  USA | SWM | Olympics | 1996 | 1–0–0 1998 Perth gold: 4×100 m medley relay (swam in heats only) | 
| Joe Bottom |  USA | SWM | Olympics | 1976 | 7–1–0 1973 Belgrade SWI gold: 4×100 m freestyle relay and 4×100 m medley relay, silver: 100 m butterfly; 1975 Cali SWI gold: 4×100 m freestyle relay (swam in heats only) and 4×100 m medley relay (swam in heats only); 1978 West Berlin SWI gold: 100 m butterfly, 4×100 m freestyle relay (swam in heats only), and 4×100 m medley relay | 
| David Boudia |  USA | DIV | Olympics | 2008—2016 | 0–4–1 2007 Melbourne DIV bronze: synchronized platform; 2009 Roma DIV silver: synchronized platform; 2011 Shanghai DIV silver: platform; 2013 Barcelona DIV silver: platform; 2015 Kazan DIV silver: platform | 
| Marie-Pierre Boudreau-Gagnon |  CAN | SWA | Olympics | 2008—2012 | 0–0–3 2009 Roma SYN bronze: solo Technical and team Free Routine Combination; 2011 Shanghai SYN bronze: team Free Routine Combination | 
| Lorys Bourelly |  FRA | SWM | Olympics | 2016 | 1–0–0 2015 Kazan SWI gold: 4×100 m freestyle relay (swam in heats only) | 
| Fréd Bousquet |  FRA | SWM | Olympics | 2000—2016 | 0–1–5 2003 Barcelona SWI bronze: 4×100 m freestyle relay; 2007 Melbourne SWI bronze: 4×100 m freestyle relay; 2009 Roma SWI silver: 50 m freestyle, bronze: 100 m freestyle and bronze: 4×100 m freestyle relay; 2013 Barcelona SWI bronze: 50 m butterfly | 
| George Bovell |  TTO | SWM | Olympics / Other | 2000—2016 | 0–0–1 2013 Barcelona SWI bronze: 50 m freestyle | 
| Alessandro Bovo |  ITA | WPO | Olympics | 1992—1996 | 1–0–0 1994 Roma WAP gold | 
| Lauren Boyle |  NZL | SWM | Olympics | 2008—2016 | 0–2–3 2013 Barcelona SWI bronze: 400 m freestyle, 800 m freestyle, and 1500 m freestyle; 2015 Kazan SWI silver: 800 m freestyle and 1500 m freestyle | 
| Ralf Braun |  GER | SWM | Olympics | 1996—2000 | 0–1–0 1998 Perth SWI silver: 200 m backstroke | 
| Dirk Braunleder |  FRG | SWM | Olympics | 1976 | 0–2–0 1975 Cali SWI silver: 4×100 m freestyle relay and 4×100 m medley relay (swam in heats only) | 
| Fruzsina Brávik |  HUN | WPO | Olympics | 2008 | 1–0–0 2005 Montréal WAP gold | 
| Emiliano Brembilla |  ITA | SWM | Olympics | 1996—2008 | 0–2–1 1998 Perth SWI silver: 1500 m freestyle; 2001 Fukuoka SWI silver: 4×200 m freestyle relay, bronze: 400 m freestyle | 
| Chris-Carol Bremer |  GER | SWM | Olympics | 1992—1996 | 0–0–1 1994 Roma SWI bronze: 200 m butterfly | 
| Janice Bremner |  CAN | SWA | Olympics | 1996 | 0–1–0 1994 Roma SYN silver: team | 
| Rosalind Brett |  GBR | SWM | Olympics | 2000 | 0–1–0 2001 Fukuoka SWI silver: 4×100 m freestyle relay | 
| Serhiy Breus |  UKR | SWM | Olympics | 2008 | 0–0–1 2005 Montréal SWI bronze: 50 m butterfly | 
| Darko Brguljan |  MNE | WPO | Olympics | 2016 | 0–1–0 2013 Barcelona WAP silver | 
| Draško Brguljan |  MNE | WPO | Olympics / Other | 2008—2020 | 1–1–0 1986 Madrid WAP gold (competed for Yugoslavia); 2013 Barcelona WAP silver (competed for Montenegro) | 
| Karin Brienesse |  NED | SWM | Olympics | 1988—1996 | 0–1–2 1986 Madrid SWI bronze: 4×100 m freestyle relay; 1991 Perth SWI silver: 4×200 m freestyle relay, bronze: 4×100 m freestyle relay | 
| Enith Brigitha |  NED | SWM | Olympics | 1972—1976 | 0–1–4 1973 Belgrade SWI silver: 200 m backstroke, bronze: 100 m freestyle; 1975 Cali SWI bronze: 100 m freestyle, 200 m freestyle, and 4×100 m medley relay | 
| Melissa Briley |  USA | DIV | Olympics | 1976 | 0–0–1 1978 West Berlin DIV bronze: platform | 
| Brian Brinkley |  GBR | SWM | Olympics | 1972—1976 | 0–1–3 1975 Cali SWI silver: 4×200 m freestyle relay, bronze: 200 m freestyle, 200 m butterfly, and 4×100 m medley relay | 
| Grant Brits |  AUS | SWM | Olympics | 2008 | 0–1–0 2007 Melbourne SWI silver: 4×200 m freestyle relay | 
| Leith Brodie |  AUS | SWM | Olympics | 2008 | 0–0–1 2005 Montréal SWI bronze: 4×100 m freestyle relay | 
| Peter Broscienski |  FRG | SWM | Olympics | 1976 | 0–1–0 1978 West Berlin SWI silver: 4×100 m medley relay (swam in heats only) | 
| Mike Brown |  CAN | SWM | Olympics | 2004—2008 | 0–1–0 2005 Montréal SWI silver: 200 m breaststroke | 
| Peter Bruch |  GDR | SWM | Olympics | 1972 | 0–0–1 1973 Belgrade SWI bronze: 4×100 m freestyle relay | 
| Annika Bruhn |  GER | SWM | Olympics | 2012—2020 | 0–0–1 2015 Kazan SWI bronze: 4×100 m medley mixed relay | 
| Daniëlle de Bruijn |  NED | WPO | Olympics | 2000—2008 | 0–1–0 1998 Perth WAP silver | 
| Inge de Bruijn |  NED | SWM | Olympics / Other | 1992—2004 | 4–0–1 1991 Perth SWI bronze: 4×100 m freestyle relay; 2001 Fukuoka SWI gold: 50 m freestyle, 100 m freestyle, and 50 m butterfly; 2003 Barcelona SWI gold: 50 m butterfly | 
| Mike Bruner |  USA | SWM | Olympics | 1976 | 1–0–0 1978 West Berlin SWI gold: 200 m butterfly | 
| Rachele Bruni |  ITA | OWS | Olympics | 2016—2020 | 0–1–2 2017 Budapest SWI bronze: 4×1.25 km open water relay; 2019 Gwangju SWI silver: 4×1.25 km open water relay, bronze: 10 km open water | 
| Olga Brusnikina |  RUS | SWA | Olympics | 1996—2004 | 4–0–0 1998 Perth SYN gold: duet and team; 2001 Fukuoka SYN gold: solo; 2003 Barcelona SYN gold: team | 
| Hannah Buckling |  AUS | WPO | Olympics | 2016—2020 | 0–1–1 2013 Barcelona WAP silver; 2019 Gwangju WAP bronze | 
| Barbara Bujka |  HUN | WPO | Olympics | 2012—2016 | 0–0–1 2013 Barcelona WAP bronze | 
| Luka Bukić |  CRO | WPO | Olympics | 2016—2020 | 0–1–1 2013 Barcelona WAP bronze; 2015 Kazan WAP silver | 
| Perica Bukić |  CRO  YUG | WPO | Olympics / Other | 1984—1996 | 2–0–0 1986 Madrid WAP gold (competed for Yugoslavia); 1991 Perth WAP gold (competed for Yugoslavia) | 
| Ivan Buljubašić |  CRO | WPO | Olympics | 2012 | 1–0–2 2009 Roma WAP bronze; 2011 Shanghai WAP bronze; 2017 Budapest WAP gold | 
| Carmen Bunaciu |  ROU | SWM | Olympics | 1980—1984 | 0–0–1 1982 Guayaquil SWI bronze: 200 m backstroke |