London Buses route SL3

London Buses route SL3 is a Transport for London contracted Superloop express bus route in London, England. Running between Thamesmead and Bromley North station, it is operated by Stagecoach London.

The route partially parallels routes 269 and 301.

History
On 21 July 2023, a consultation for route SL3 was opened by Transport for London, and closed on 4 September the same year. The route parallels part of route 301 between Thamesmead and Bexleyheath, and part of route 269 between Bexleyheath Shopping Centre and Bromley North station. Route SL3 was awarded to Stagecoach London on 20 October. TfL claimed that 67% of the feedback it received reflected that route SL3 would make their journeys more convenient, and 70% said the new route would reduce their travel time.

Route SL3 was introduced on 24 February 2024, using New Routemasters. It is operated by Stagecoach London.

After a competitive tendering process, the contract was retained by Stagecoach London from January 2025 with the New Routemasters to be replaced by brand new Alexander Dennis Enviro400EVs.

Current route
Route SL3 operates via these primary locations:
 * Thamesmead
 * Abbey Wood station
 * Bexleyheath station
 * Bexleyheath Shopping Centre
 * Sidcup station
 * Queen Mary's Hospital
 * Chislehurst War Memorial
 * Chislehurst station
 * Bickley station
 * Bromley North station

Operation
The route operates at a frequency of a bus every 12 minutes on weekdays and Saturdays and a bus every 15 minutes on Sundays.