Tranmere is a suburb of Birkenhead, on the Wirral Peninsula, England. Administratively, it is also a ward of the Metropolitan Borough of Wirral. Before local government reorganisation on 1 April 1974, it was part of the County Borough of Birkenhead, within the geographical county of Cheshire. At the 2001 Census, the population of Tranmere was 11,668 (5,399 males, 6,269 females).