Castor Bay is a bay and suburb of Auckland in the North Island of New Zealand. Located between Milford and Campbells Bay, it is part of the East Coast Bays. To the east lies the islands of Rangitoto and Motutapu, which are easily visible from land. The suburb is in the North Shore ward, one of the thirteen administrative divisions of Auckland City. The population was 2,877 in the 2006 Census, an increase of 93 from 2001. Sam Hunt, one of New Zealand's most well known poets, was born in Castor Bay.