Ap Chau, also known as Robinson Island, with a size of 0.04 km² is an island in the Crooked Harbour, in the north-eastern New Territories of Hong Kong. It is located in Ap Chau Bay and is under the administration of North District. The island had 8 inhabitants as of June 2008. Islets located close by include Ap Chau Pak Tun Pai, Ap Chau Mei Pak Tun Pai, Ap Lo Chun, Ap Tan Pai and Kau Tau Shek.
Robinson Island was named after Hercules Robinson, 1st Baron Rosmead, who was the 5th Governor of Hong Kong from 1859 to 1865.