RNAS Calshot was a First World War Royal Navy air station for seaplanes and flying boats, mainly operating as an experimental and training station, but also providing anti-submarine and convoy protection patrols.

It was located at the end of Calshot Spit in Southampton Water, at grid reference SU487024, with the landing area sheltered by the mainland, to the west, north and east, and the Isle of Wight a few miles away to the south on the other side of the Solent.

The station was originally established on 29 March 1913 by the Royal Flying Corps (RFC),[1] as Calshot Naval Air Station, for the purpose of testing seaplanes for the RFC Naval wing.

A major rebuild at Calshot then took place when new buildings, offices and workshops were constructed by the Henry Boot Limited.

[3] On 1 April 1918 the RFC and the RNAS combined to form the Royal Air Force (RAF) and the station became home to the headquarters of No.