Ma Shi Chau (Chinese: 馬屎洲 Cantonese: ma5 si2 zau1, literally meaning "horse excrement island") is an island of Hong Kong, under the administration of Tai Po District. It is located in Tolo Harbour in the northeast New Territories (near Sam Mun Tsai). It is connected with another island, Yim Tin Tsai, by a narrow strip of land that is only accessible when the tide is low.