The British Rail Class 170 Turbostar is a British diesel multiple unit (DMU) passenger train designed and built by Adtranz, and later by Bombardier Transportation, at Derby Litchurch Lane Works. The Class 170 was derived from the British Rail Class 165 and 166 DMUs, known as the Networker Turbos, of the 1990s.

The class 170 "Turbostar" is the diesel hydraulic multiple unit designed for longer distance services from builders Adtranz, now Bombardier. Vehicles, which are of nominal 23m long, are of welded aluminium with steel ends construction and all cars are motored providing 422h.p. @ 1900 r.p.m. per car.