Belsize is a ward in the London Borough of Camden, in the United Kingdom. The ward covers most of Belsize Park, between Haverstock Hill, Swiss Cottage, and Primrose Hill. The population of this ward at the 2011 Census was 12,702. The ward has existed since the creation of the borough on 1 April 1965 and was first used in the 1964 elections. The ward was redrawn in May 1978, May 2002, and May 2022.