Tory Sir Graham Brady, the then leader of the 1922 Committee of backbenchers, had held this seat since 1997.
Sir Brady announced in March that he would not be standing for re-election.
The seat has now turned Labour red.
The constituency is known as a highly affluent area, encompassing Hale Barns, where many famous faces live.
Sir Brady rose to prominence recently after his role as leader of the 1922 Committee, which collects votes of no-confidence in the Prime Minister.
The results in full:
Jane Brophy, Liberal Democrats: 4,727
Oliver Carroll, Conservative: 16,624
Geraldine Coggins, Green: 3,699
Faisal Kabir, Workers Party: 643
Connor Rand, Labour: 20,798
Paul Swansborough, Reform UK: 4,961
