Birkenhead is a north-western suburb of Adelaide 14 km from the CBD, on the Lefevre Peninsula, in the state of South Australia, Australia, and lies within the City of Port Adelaide Enfield. It is adjacent to Peterhead, Exeter and Glanville. It is bounded to the south by the Gawler Reach of the Port River, to the north by Hargrave Street and in the west and east by the Outer Harbor railway line and the Port River respectively.
It was laid out on section 700, Hundred of Port Adelaide by Thomas Elder and John Hart. Birkenhead Post Office opened around 1884.
Birkenhead is essentially a residential suburb, with industrial harbourside development on the southern and eastern shores of the suburb. It is notable for the Birkenhead Bridge, which formerly opened on a regular basis so that boats could pass along the Port River. It is also the site of a third Port River crossing, the Port River Expressway. It includes the opening Tom "Diver" Derrick bridge, designed to ease traffic congestion in the area and opened in August 2008, adjacent to the opening Mary MacKillop railway bridge.
The Birkenhead Bridge and the former HMAS Encounter Naval Drill Hall are listed on the South Australian Heritage Register.