Ann O’Connor competed in the women’s 100 metres breaststroke and 200 metres breaststroke at two consecutive Olympic Games – the 1968 Mexico City Games and the 1972 Munich Games – having first qualified for Mexico at the age of sixteen, at which point she already held five national breaststroke titles and had set a new Irish record in the 100 metres breaststroke (1:18.0) in an early-season international against Iceland.

One of four Irish swimmers selected for Mexico in a decade of significant advancement in Irish swimming, she also competed in the women’s 4×100 metres freestyle relay and 4×100 metres medley relay alongside Vicki Smith, Brenda McGrory and Aisling O’Leary.

Given the youth of O’Connor and Smith, the OCI appointed Jane McVeigh as chaperone to accompany them to the Games. At Munich in 1972 she finished 26th in the 100 metres breaststroke and 29th in the 200 metres breaststroke. In 1969 she won the ASA National British Championships title in the 110 yards breaststroke.