F
- Fastrack
- Felix Bus Services
- Fife Scottish
- First Aberdeen
- First Berkshire & The Thames Valley
- First Bristol
- First Chester & The Wirral - No longer operating, (Sold to Stagecoach)
- First Cymru
- First Devon & Cornwall
- First Eastern Counties
- First Edinburgh
- First Essex
- First Glasgow
- First Greater Manchester
- First Hampshire & Dorset
- First Leicester
- First London
- First Midland Red
- First Potteries
- First Somerset & Avon
- First South Yorkshire
- First Stop Travel
- First Student UK
- First West Yorkshire
- First Bradford
- First Calderdale & Huddersfield
- First Leeds
- First York
- Fleet Buzz
- Flexibus
- Flights Hallmark
- FreeCityBus
Read more about this topic: List Of Bus Operators Of The United Kingdom