Heidi Suzanne Allen is a British politician who served as the Member of Parliament for South Cambridgeshire from 2015 to 2019. Initially elected as a Conservative, she resigned from the party in February 2019, joining and later serving as leader of Change UK. She resigned from Change UK in June of the same year, and joined the Liberal Democrats in October 2019. She announced on 29 October that she would not stand for re-election at the next general election.