Birkdale is an area of Southport, within the Metropolitan Borough of Sefton, Merseyside, though historically in Lancashire, in the north-west of England. The area is located on the Irish Sea coast, approximately a mile away from the centre of Southport. At the 2001 census, the local government ward called Birkdale had a population of 12,265. The po…Birkdale is an area of Southport, within the Metropolitan Borough of Sefton, Merseyside, though historically in Lancashire, in the north-west of England. The area is located on the Irish Sea coast, approximately a mile away from the centre of Southport. At the 2001 census, the local government ward called Birkdale had a population of 12,265. The population of the area at the 2011 Census is shown under Birkdale. Other parts of Birkdale are included in Dukes ward—which contains a significant part of the village centre and the Royal Birkdale Golf Club—Kew and Ainsdale wards.