Milsons Passage, situated in the shire of Hornsby, is the channel between Milson Island in the Hawkesbury River and the mainland to the west. Its previous names have been The Gutter and South Channel. The Geographical Names Board officially named the waterway Milsons Passage in 1976, and the settlement on the western shore (Prickly Point) was named the suburb of Milsons Passage in 1995. 
The passage and the island take their name from Robert Milson, who between 1863 and 1869 purchased the island and three parcels of land on the western shore, where he lived. He was the son of James Milson who owned land at Milsons Point on Sydney Harbour. 
During the twentieth century, a number of houses were built along the western shore's waterfront, especially after the auction of a major subdivision in 1939. 
A Progress Association for the Milsons Passage settlement was formed in 1939 to campaign for infrastructure. A road from Kangaroo Point was never built, despite the Association's efforts, but electricity arrived in 1942–43. 
In 2006 the population was 571 people, down 27 from the 1996 census.
John Carrick, The History of the River Settlement of Milsons Passage, the author, Sydney, 2006