Birkenhead is a north-western suburb of Adelaide 14 km from the CBD, on the Lefevre Peninsula, in South 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.

Adelaide Metro route 150 bus services operate along Semaphore and Fletcher Roads, while routes 352 and 353 serves Semaphore and Fletcher Roads and Hargrave Street. Routes 333 and N254 serve Semaphore Road. The suburb also is serviced by Peterhead railway station on the Outer Harbor railway line.