Helen Gradwell Varcoe (18 February 1907 – 7 May 1995), later known by her married name Helen Nicholls, was an English competitive swimmer who represented Great Britain at the 1932 Summer Olympics in Los Angeles.
Varcoe won a bronze medal swimming the anchor leg for the British women's team in the 4×100-metre freestyle relay, together with her teammates Joyce Cooper, Valerie Davies and Edna Hughes.
The British women finished third with a time of 4:52.4, behind the Americans (4:38.0) and Dutch (4:47.5), and ahead of the Canadians (5:05.7).Varcoe was born in Croydon, London, and died in Truro, Cornwall.