The South London line is a railway line in inner south London, England. The initial steam passenger service on the route was established by the London, Brighton and South Coast Railway (LBSCR) on 1 May 1867 when the central London terminal stations of Victoria and London Bridge were connected to the inner south London suburbs of Battersea, Clapham, Brixton, Camberwell and Peckham. A pioneer of overhead electric traction, most of the line was built on high level viaducts and was marketed as the South London Elevated Electric Railway in the early part of the 20th century. The electric service was popular, with four trains per hour and 12 million passengers in 1920. Between Wandsworth Road and Peckham Rye the route ran parallel to another set of tracks. Prior to 1923, both lines from Wandsworth Road to East Brixton were owned by the London, Chatham and Dover Railway (LCDR) and the lines from East Brixton to Peckham Rye were owned by the LBSCR. The southern Atlantic lines were operated by the LBSCR and the northern Chatham lines were operated by the LCDR.
The LBSCR and LCDR were both constituent companies of the Southern Railway (SR) and consequently the whole line came into SR ownership in 1923. Overhead traction was replaced with third rail in 1928. This began a long, slow period of decline that culminated in the running of only nine trains a day in each direction at peak times in 1988. The line was revived following a successful campaign by the South London Line Travellers Association. The full seven day half-hourly timetable was restored in stages from 1991 to 1997. Since December 2012, passenger services have been part of the London Overground, running a four trains an hour service between Clapham Junction and Queens Road Peckham and then via the East London line to Dalston Junction. In November 2024, the London Overground East London and South London line services were rebranded and named the Windrush line.