The Fiat 509 was a model of car produced by Italian automotive manufacturer Fiat between 1925 and 1929 as a replacement for the 501.

Approximately 90,000 of the model were sold.

For 1928, the 509 was offered with standard insurance, also.

[1] In addition to as the standard car, there were 509S and 509SM sports models, as well as taxi and commercial versions.

The Fiat 509 was fitted with a 990 cc overhead cam engine.