Coordinates: 50°11′31″N 5°26′06″W / 50.192°N 5.435°W
The Hayle Estuary (Cornish: Heyl, meaning estuary) is an estuary in west Cornwall, England, United Kingdom.
The estuary of the River Hayle consists of a main channel, with several other nearby tidal areas, including Lelant Saltings, Copperhouse Creek (Cornish: Est Logh, meaning eastern inlet) and Carnsew Pool (also known as Carnsew Basin).
It is included in the Hayle Estuary and Carrack Gladden Site of Special Scientific Interest.
The Royal Society for the Protection of Birds manages a nature reserve at the site.
The road over the estuary was originally a turnpike road which was overseen by the winner of a public auction. For the year 1880, the winning bid was £591 10s.