Otto Wahle swam at both the 1900 Paris and 1904 St. Louis Olympics, winning two silver medals (1,000 metres freestyle and 200 metres obstacle course in 1900) and a bronze medal (440 yards freestyle in 1904). He was an Austrian national until 1906 when he became a US citizen, after settling in New York. He represented Austria at both the 1900 and 1904 Olympics despite representing the New York Athletic Club at the latter Games. In 1897, he was German national champion over 100 metres freestyle.
In New York, Wahle put his emphasis on working with swimmers. He became a swimming coach and was responsible for the US swimming team at the 1912 Olympics and for the water polo teams at the 1920 and 1924 Games. One of his closest friends was Karl Ruberl, another Austrian swimmer who also emigrated to the USA.
As an AAU committeeman, Wahle helped to formulate and interpret the rules of swimming as they were developed over the years. In 1996, Wahle was inducted into the International Swimming Hall of Fame. Wahle earned his living as an accountant and was also known for his keen interest and appreciation of classical music and, over the years, built an extensive collection of 78 RPM records.