London Buses route 21

London Buses route 21 is a Transport for London contracted bus route in London, England. Running between Holloway and Lewisham Shopping Centre, it is operated by Go-Ahead London.

History
In 2018, an Optare MetroDecker EV prototype was trialed on the route.

In November 2021, the frequency of the service was reduced from 6-8 minutes to 8-10 minutes.

On 4 February 2023, route 21 was withdrawn between Newington Green and Hoxton and extended to Holloway partially replacing the daytime route 271, following a successful consultation in early 2022.

Current route
Route 21 operates via these primary locations:
 * Lewisham Shopping Centre
 * Lewisham station
 * St Johns station
 * New Cross Gate station
 * Old Kent Road
 * Bricklayers Arms
 * Borough station
 * London Bridge station
 * Bank and Monument stations
 * Moorgate station
 * Moorfields Eye Hospital
 * Essex Road railway station
 * Highbury & Islington station
 * St Mary Magdalene Church
 * Holloway Road station
 * Holloway Nag's Head

Incident
On 1 April 2017, a number 21 bus blocked the street in Cornhill as it became stuck after mounting the curb during an attempted three-point turn.