The Westland Weasel was a prototype British two-seat fighter/reconnaissance aircraft of the First World War.

Designed to replace the Bristol Fighter, the Weasel was a single engined tractor biplane.

The Westland Weasel was designed by Westland Aircraft of Yeovil to meet the Royal Air Force's Type IIIA Specification for a two-seat fighter/reconnaissance aircraft to replace the successful Bristol Fighter.

[2][3] Like the other two competitors, the Weasel was powered by the officially encouraged ABC Dragonfly 9-cylinder air-cooled radial engine.

[1] These problems were unsolvable, and although the Weasel had slightly better performance than the Bristol and Austin designs, the failure of the Dragonfly and the lack of urgent need to replace the excellent Bristol Fighter meant that large scale orders did not follow.