Citizens band radio (often shortened to CB radio) is a system of short-distance radio communications between individuals on a selection of 40 channels within the 27-MHz (11 m) band. In the United Kingdom, CB radio was first legally introduced in 1981, but had been used illegally for some years prior.

In December 2006, CB radio was deregulated by Ofcom and it is now licence-free. Although the use of CB radios in the UK has declined from its peak, it is still popular, especially with the farming community, Land Rover owners and Mini-Cab services. It is also fitted as standard to 'Street Glide' and 'Electra Glide' models of Harley Davidson touring motorcycles sold in the UK.

Countless CB related clubs and groups have existed over the years, including some more notable organisations:

• NATCOLCIBAR (NATional COmmittee for the Legalisation of CItizens BAnd Radio)
• REACT UK (Radio Emergency Associate Communications Team – later changed to Radio Emergency And Citizens Teams)
• MSGB (Monitoring Services of Great Britain)
• THAMES (Traffic Help And Monitoring Emergency Service)
• REVCOM (Radio Emergency Volunteer Communications)

To reiterate, use of CB radio is legal in the UK without licence. Certain channels (like 9 and 19) are reserved to emergency service and truckers, respectively, but the rest of free to all.