Mitcham Junction is a National Rail station served by Southern and Thameslink trains, and a Tramlink stop. It is in the London Borough of Merton and is in Travelcard Zone 4.

Southern is the brand name used by the Govia Thameslink Railway (GTR) train operating company on the Southern routes of the Thameslink, Southern and Great Northern franchise in England. It is a subsidiary of Govia, a joint venture between transport groups Go-Ahead and Keolis, and has operated the South Central franchise since August 2001 and the Gatwick Express service since June 2008. When the passenger rail franchise was subsumed into GTR, Southern was split from Gatwick Express and the two became separate brands, alongside the Thameslink and Great Northern brands.