The Leyland Eight was a luxury car produced by Leyland Motors from 1920 to 1923. The car was designed by the chief engineer of Leyland Motors, J.G. Parry-Thomas and his assistant Reid Railton, and was intended to be the finest car available. The Eight was introduced to the public at the 1920 International Motor Exhibition at Olympia, London, where it was referred to as the "Lion of Olympia".

Two engine options were offered: a 6,920 cc capacity unit producing 115 bhp or 7,266 cc with twin carburettors producing 145 bhp. Both had a single overhead camshaft and hemispherical combustion chambers. The chassis had elliptical leaf springs at front and rear. The brakes, with vacuum servo, were on the rear wheels only.

Factory-made bodies were available in open tourer style with either two or five seats and chassis were also supplied to coachbuilders. The car was very expensive, the chassis for delivery to a coachbuilder costing £2,500 in 1920 reducing to £1,875 in 1922 and only about 18 were made. It was the most expensive British car of its day. Today, only one example of this car is known to exist, and it resides in a transport museum.

Michael Collins, the Irish politician and revolutionary leader, was travelling in a Leyland Eight when he was fatally shot in 1922.

Leyland engineer J. G. Parry-Thomas built the Leyland-Thomas, a racing special based on the Leyland Eight.