Great Crosby, commonly known as just "Crosby" is a town in Sefton, Merseyside, North West England.

Crosby grew up during the late 19th and early 20th century and comprises a number of distinct areas with their own character.

• Blundellsands: middle class residential area close to the sea front
• Crosby: the main area for shops, pubs and restaurants
• Thornton: mainly 1930s era residential area, semi-detached and detached housing

Most residents commute to Liverpool to work either by car, bus or on the electric train service from Blundellsands & Crosby and Hall Road stations.

Crosby has a cinema, two fee-paying schools (Merchant Taylors' and St Mary's) and pleasant parks facing the sea.

Great Crosby was an urban district in its own right and later merged with Little Crosby and Waterloo with Seaforth to form the Borough of Crosby. This in turn was absorbed into the new Metropolitan Borough of Sefton in 1974.