The A20 is a major road in England, running from London to Dover in Kent.

From its origin, a junction with the A2 road near Greenwich, the road runs south east past Lewisham and Sidcup. Entering Kent, it runs past Swanley and Brands Hatch, then through Maidstone, Ashford, Hythe and Folkestone before terminating at the docks in Dover.

The section of the road near Kent is closely paralleled by the M20 motorway.