Ōmura (大村市; - shi) is a city of the Japan located in the Préfecture of Nagasaki.

In 2005, the city had a population estimated at 90,000 inhabitants for a density of 683,83 hab/km ². Total surface area of the east city 126.33 km ²

The city was founded the February 11th 1942. The name of the city is mentioned in the opera Mrs Butterfly.