The Riley 8/90 was an automobile of the upper middle class which Riley brought out in 1935.

The cars had a V8 OHV engine which was constructed of two 4-cylinder engines. This 2178 cc engine produced ​​80 bhp (59 kW). The roadster had a top speed of 131 km/h.

After a short time during the same year, production was ceased as the model was not a success.

As the successor, in 1937 the Riley 2 1/2 appeared.