Gus Dillon took up lacrosse in the 1900s and was a member of Montreal’s Shamrock Lacrosse Club when he was selected to represent Canada in the sport at the 1908 Summer Olympics. There he earned a gold medal with his team after it won its only match against Great Britain 14-10. He remained active in lacrosse for several more years, until his retirement from active competition in 1911.
Name previously given as Angus Dillon, but this is not supported by his obituary and contemporary Montreal newspapers.