First Bus London
New Routemaster on route 148 at St Thomas' Hospital in July 2025 | |
| Parent | FirstGroup |
|---|---|
| Founded | February 28, 2025 |
| Headquarters | London |
| Service area | Greater London |
| Service type | Bus operator |
| Hubs | North-west London West London South-west London |
| Depots | 10 |
| Fleet | 1,007 (March 2025) |
| Fuel type | Diesel, Hybrid and Electric |
| Managing directors | Colin Brown Bill Cahill |
| Website | www.firstbus.co.uk |
First Bus London is a bus operator running services across Greater London, England. It is a subsidiary of FirstGroup, operating buses under contract to Transport for London, and was formed with the purchase of RATP Dev Transit London from RATP Group in 2025.