Streatham St Leonard's is an electoral ward in the London Borough of Lambeth, United Kingdom.

It is located in the south west of the borough and shares a border with Wandsworth.

The ward comprises the western part of the Streatham town centre and is mostly to the west of the A23 Streatham High Road, with the exception of the Stanthorpe Triangle area immediately east of St Leonard's church in the historic village centre.

[1] St Leonard's ward is located in the Streatham Parliamentary constituency.

The local Member of Parliament since 2019 is Bell Ribeiro-Addy of the Labour Party.

Future Speaker of the House of Commons John Bercow served as a councillor here from 1986 to 1990.