Sian Rainsley (born 19 April 1997) is a British triathlete.

She competed at the 2014 Youth Olympic Games winning a silver medal, 2021 European Triathlon Championships winning a bronze medal,[1][2] 2022 World Triathlon Championship Series Leeds finishing 15th,[3][4] and 2022 World Triathlon Championship Series Hamburg, finishing first.

[5] She was named to the 2022 Commonwealth Games, team England.

[7] She was diagnosed with Crohn's Disease.

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