The Bakerloo line runs from Harrow & Wealdstone in suburban north-west London to Elephant & Castle in south London, via the West End.

Printed in brown on the Tube map, it serves 25 stations, 15 of which are underground, over 14.4 miles (23.2 km). It runs partly on the surface and partly in deep-level tube tunnels.

The line is so named because it runs via Baker Street and Waterloo.

The Bakerloo line is currently served by three depots: a main depot at Stonebridge Park, opened on 9 April 1978 on the site of a former British Rail power station which contains the fleet's maintenance facilities; the original depot at London Road (between Elephant and Castle and Lambeth North, though connected to the line between Lambeth North and Waterloo); and a small depot immediately north of Queens Park, built in 1915. The Queens Park depot is unique on the London Underground network in that trains in passenger service run through it.