Named after Dagenham and the Heathway, the road that leads to Becontree Heath.
Dagenham almost certainly means the farm of a man called Dæcca, written Dæccanhaam in a charter dated 666. The station opened in 1932 as plain Heathway, on a site picked in 1920 by the Midland Railway and the London County Council, builder of the new Becontree estate. Dagenham Council pushed for the name Dagenham Central, but in 1949 it became Dagenham Heathway.