British record holder Siobhan-Marie O’Connor is a former competitive swimmer who represented England at the Olympic Games, FINA World Aquatics Championships, LEN European Aquatics Championships, and Commonwealth Games. She won silver medals in the 200m individual medley at the 2014 Commonwealth Games, the 2015 World Aquatics Championships, the 2016 European Aquatics Championships, the 2014 World Short-Course Championships, and the 2013 and 2015 European Short Course Championships – all behind World and Olympic champion Katinka Hossz. At the 2014 Commonwealth Games, O’Connor was England’s most decorated athlete, winning six medals in total.

O’Connor went to Bath’s St. Gregory’s Catholic College. She skipped prom to compete in the 2012 London Olympics qualifying meet. Siobhan was at a Team Bath warm weather training camp at Northern Arizona University in 2015 when four students were shot by a freshman after a fight outside a fraternity home, with one killed and three injured. Despite the fact that she was asleep in another section of campus at the time of the shooting, she was severely affected by it.

At the 2015 FINA World Aquatics Championships, O’Connor swam the butterfly leg for Great Britain in the non-Olympic 4 x 100-meter mixed medley relay, which won gold in a world record time. In 2016, she also won gold in the same event at the European Championships in the women’s 4 x 100 meter medley relay. At the 2012 Summer Olympics, O’Connor first represented Great Britain in the 100m breaststroke event. She has British records in the 200-meter individual medley, the 100-meter breaststroke, and the four-person 100-meter mixed medley relay. O’Connor announced her retirement from competitive swimming in June 2021, after a long battle with ulcerative colitis.