Chesham and Amersham (/ˈtʃɛʃəm ... ˈæmərʃəm/ CHESH-əm ... AM-ər-shəm) is a parliamentary constituency in Buckinghamshire, South East England, represented in the House of Commons by Sarah Green, a Liberal Democrat elected at a 2021 by-election.

It includes the towns of Chesham, Amersham and Gerrards Cross, together with outlying villages within the Metropolitan Green Belt.

The two main towns are the only part of the London Underground network amid an Area of Outstanding Natural Beauty (viz Chiltern Hills).

Dame Cheryl Gillan MP died in office on 4 April 2021, and the seat was gained by the Liberal Democrats' pro-EU Sarah Green in the subsequent by-election on 17 June 2021 with a majority of 8,028 votes.

[6] The Liberal Democrat win in the 2021 Chesham and Amersham by-election was seen as an upset in a historically safe Conservative seat,[6] and party leader Sir Ed Davey tweeted that the result had "sent a shockwave through British politics".

[8] Sarah Green retained the seat for the Liberal Democrats at the 2024 General Election with a swing of 22.4%, giving her a majority of 5,451 (10.0%).