Syon and Brentford Lock is an electoral ward in the London Borough of Hounslow. The ward was first used in the 2022 elections. It returns three councillors to Hounslow London Borough Council.
The by-election took place on 6 March 2025, following the resignation of Balraj Sarai. It was held on the same day as the 2025 Brentford East by-election.
The election took place on 5 May 2022.