Kau Sai Chau  is an island located off the coast of Sai Kung of Hong Kong, with an area of 6.70 km2, making it the 6th largest island of Hong Kong. It is under the administration of Sai Kung District.

    The Jockey Club Kau Sai Chau Public Golf Course, developed and run by the Hong Kong Jockey Club, is the only public golf course in Hong Kong. Opened in 1995, it occupies approximately the northern half of the island. It comprises three 18-hole golf courses: the North and South Courses were designed by Gary Player, while Nelson & Haworth designed the East Course.

    Kau Sai Village is a small fishing hamlet with about ten houses. It is located at the southern tip of the island.

    Two declared monuments of Hong Kong are located on Kau Sai Chau: a prehistoric rock carving and a Hung Shing Temple:

    The prehistoric rock carving was discovered in 1976. It is located on the north-western coast of the island, in a location "where accessibility by land is extremely poor".

     The Hung Shing Temple is located in the southern part of the island, near Kau Sai Village, of which it is the only temple.The building was built before 1889. It is constructed in grey bricks with a timber roof frame. The temple has been renovated four times, in 1949, in the 1970s, in 1988 and the last being from August 1999 to February 2000.  The restoration was declared an "Outstanding Project" by the UNESCO Asia-Pacific Heritage 2000 Awards. Previously a Grade III Historic Building, the temple was declared a monument on November 15, 2002. The Hung Shing Festival  is celebrated there on the 13th day of the 2nd month in Chinese calendar.