The Simca Poissy engine, commonly known as the Simca 1100 engine, was a four-cylinder Overhead valve engine developed by Simca for use in its superminis and economy cars, designed by the engineer Georges Martin. In spite of its common name, the engine actually predates the Simca 1100 model, and debuted in 1961 in the Simca 1000. It was developed and produced by Simca in the late 1960s at the manufacturer's factory in Poissy, hence its name.

The Simca 1100 are a series of French compact family cars – mainly C-segment hatchbacks, but also a compact wagon and popular delivery vans – built for over 15 years by French car-maker Simca, from 1967 through 1982/1985. There was even a very early 'hot hatchback', and a family cross-over: the Matra Simca Rancho. The hatchbacks were replaced by the Simca-Talbot Horizon.