The M20 is a motorway in Kent, England. It follows on from the A20 at Swanley, meeting the M25, and continuing on to Folkestone, providing a link to the Channel Tunnel and the ports at Dover. It is 50.6 miles (81.4 km) long. Although not signposted in England, this road is part of the European route E15. It is also used as a holding area for goods traffic when traffic across the English Channel is disrupted, such as Operation Stack and Operation Brock.

The A20 is a major road in south-east England, carrying traffic from London to Dover in Kent. Parts of the route date back to turnpikes established in the early part of the 18th century. The line of the road throughout Kent runs closely in parallel with the M20 motorway.