Adam Mikołaj Sieniawski (1666–1726) was a Polish nobleman, aristocrat and military leader.
He was the son of Hetman Mikołaj Hieronim Sieniawski and Cecylia Maria Radziwiłł, daughter of Court and Grand Marshal Prince Aleksander Ludwik Radziwiłł. He married Elżbieta Lubomirska, daughter of Court and Grand Marshal Prince Stanisław Herakliusz Lubomirski, in 1687.
Sieniawski was voivode (governor) of Bełz Voivodeship from 1692 to 1710, Field Crown Hetman since 1702, Great Crown Hetman since 1706,