London Buses route S4 is a Transport for London contracted bus route in London, England. Running between Roundshaw and St Helier, it is operated by Abellio London.
Route S4 commenced operating on 15 November 1997 between Sutton Bushey Road and Roundshaw Neighbourhood Centre. The route was initially operated by Quality Line from their Epsom (EB) garage using UVG CitiStar bodied Varios.
In March 1998, the route was withdrawn bin Sutton between Marshalls Road and Bushey Road. In May 1998, the route was extended from Sutton to Morden via withdrawn Route 421.
In 2001, the route was converted to low floor operation using Plaxton Pointer 2 bodied Dennis Darts.
In 2002, the route was withdrawn between Sutton and Morden - this section replaced by new Route S7. At the same time, an Evening service was introduced and the Plaxton Pointer 2 bodied Dennis Dart SLFs were replaced by Optare Solos.
In 2005, the route was extended further along Mollison Drive in Roundshaw to Wilson's School.
In 2006, the route was extended from Sutton to St Helier.
In December 2006, brand new East Lancs Esteem bodied Alexander Dennis Enviro 200 Darts were introduced.
In 2007, the route was retained by Quality Line.
In 2014, the route passed to Abellio London operating from their Beddington (BC) garage using brand new Alexander Dennis Enviro 200 Darts.
- Roundshaw Wilson's School
- Woodcote Green
- Wallington Station
- Belmont Station
- Sutton Station
- St Helier Hospital
- St Helier Station