The Lanchester Armoured Car was a British armoured car produced during the First World War. It is not to be confused with an interwar period six-wheeled design.
In 1914, the Lanchester was the second most numerous armoured car in service after the Rolls-Royce. It was originally designed to support air bases and retrieve downed pilots.
In 1915, the Lanchester underwent hull remodelling and was formed into armoured car squadrons. 36 Lanchesters were delivered to the Royal Naval Air Service. Three squadrons of 12 vehicles were formed and sent to France in May. One of these squadrons served with the Belgian Army. In addition, Belgium received 10–15 car on loan from RNAS.
The Russian Army received 22 vehicles in December 1915. 19 of them were later rearmed with 37-mm naval Hotchkiss gun instead of MG. With the establishment of the mountain-to-coast trench system of the Western Front, armoured cars were of less use and the British Army taking over all armoured car use standardizes on the Rolls-Royce pattern. The Lanchesters were then sent to Russia in January 1916 with the RNAS expedition force. The expedition force was deployed in Caucasus, Romania and Galicia in support of the Russian forces there; detachments were sent as far as Persia and Turkey and the Lanchesters clocked up many thousands of miles. In early 1918 the expedition force departed Russia via Murmansk. Most of the Russian Lanchesters were used by the White Russian forces in the Russian Civil War.
During most of its service life, the Lanchester was considered a fast and reliable vehicle.