| Number: | 4 |
| Bgcolor: | red |
| Titlecolor: | white |
| Operator: | Metroline[1] |
| Garage: | Holloway |
| Predecessors: | Route 4A |
| Start: | Archway station |
| Via: | Holloway Finsbury Park Islington St Paul's Cathedral |
| End: | Blackfriars station |
| Level: | Daily |
London Buses route 4 is a Transport for London contracted bus route in London, England. Running between Archway and Blackfriars stations, it is operated by Metroline.
On 25 September 1993, the contract for route 4 was won by London Suburban Bus, who operated the route with Leyland Titans.[2]
On 27 April 1995, route 4 was included in the sale of London Suburban Bus to Metroline and in March 2000 to ComfortDelGro.[3]
In April 2019, Transport for London announced that route 4 would be withdrawn between Waterloo station and St Paul's station and extended to Blackfriars station via Queen Victoria Street instead, with the change taking effect in June of that year.[4]
Route 4 operates via these primary locations:[5]