Mikołaj Hieronim Sieniawski (1645–1683) was a Polish noble (szlachcic), military leader and politician.

He was the son of the starost of Lwów Adam Hieronim Sieniawski and Wiktoria Elżbieta Potocka, the daughter of Hetman Stanisław "Rewera" Potocki.

He became famous as a talented commander in wars against Cossacks and Tatars during the reign of King John II Casimir.

In the rank of a Chorąży he took part, alongside John Sobieski, in the Chocim expedition.

He died in the same year by contracting a disease, possibly syphilis, that spread after the battle.