A new train line connecting the borough with Canary Wharf and the city is set to open.
The extension of the Overground line, first opened five years ago, provides an orbital route connecting Clapham Junction directly with Surrey Quays.
Trains will run from Clapham Junction, through Wandsworth Road and Clapham High Street stations through to Peckham and up to Canada Water, Shoreditch High Street and Shadwell, via Surrey Quays.
It also provides connections to Croydon and Crystal Palace.
Platform two in the station has been split to accommodate existing services to Willesden Junction and Stratford, as well as the Highbury & Islington extension.
Howard Smith, chief operating officer for London Rail, said: "From December 2012, the new London Overground extension to Clapham Junction will provide a more frequent service of four trains per hour via Denmark Hill and Peckham Rye to the City and Docklands.
"TfL has also been working with Southeastern trains to investigate the possibility of calling some existing Victoria services at Peckham Rye and Denmark Hill stations.
"The Mayor has written to the Department for Transport to request that these additional stops are included in the Southeastern franchise."
Cyril Richert, of the Clapham Junction Action Group, said it reflects good public investment for the community.
He said: "The regeneration of the overground lines is great news for Clapham Junction.
"It is only a few years ago that the busiest train station in Britain first appeared on the tube map, with the link to Willesden Junction and up north.
"It reinforces the station's role as a major transport hub south of the river and should increase pressure on Network Rail to give its view on the station itself, and not only rely on small patches here and there."