Crosby Beach is part of the Merseyside coastline north of Liverpool in the Metropolitan Borough of Sefton, England.
The beach stretches about 3 miles North-West from the Seaforth Dock in the Port of Liverpool, through Waterloo, where it separates the sea from the Marina, past Crosby Swimming Baths, up beyond the coastguard station in Blundellsands to the estuary of the River Alt.
The navigable shipping channel in Liverpool Bay, connecting the River Mersey to the Irish Sea, runs parallel to the beach to around the coastguard station where it swings out to sea.
The beach has only really been stabilised in the last half a century or so. Previous to this at high tides the sea could come in as far as the first row of houses. Dune management, which is still ongoing to the present day (including the planting of old Christmas trees) and the building of a sea wall have now reduced the problems .
In the older dunes north of the coastguard station, between the sea and the West Lancashire Golf Club, there are still some remains of the old wartime defences.