The Riley 15/6 was an upper class vehicle that Riley brought out in 1934.

All models had a 1,726 cc 6-cylinder in-line engine which had a power output of 51 bhp (37.5 kW). The two models on short chassis, Falcon (4-window sedan) and Lynx (Tourer), reached 136 km/h. The two large hatchback sedans (6 windows) were called Adelphi and Kestrel.

In 1938, the 15/6 was scrapped without a successor.