Rebecca Lewis (born 1983 or 1984, known as Becky), is an English long-distance swimmer. In 2011 she swam for 35 hours 18 minutes as part of "The Swim", a relay team crossing the Irish Sea. In 2015 she broke the record for the fastest time for a two-way swim the length of Windermere, in the regular competition held by the . In 2016 she broke the record for the fastest British swimmer to make a two-way crossing of the English channel. She appeared with Paul Rose in the "Windermere" episode of his 2018 BBC One series The Lakes with Paul Rose. She is a physiotherapist and works in Barrow in Furness.