Michał Kazimierz Pac (, ; 1624 – 4 April 1682 in Wace near Vilna) was a magnate of the Grand Duchy of Lithuania and a member of the Pac family. He was a son of Stefan Pac and a brother of Krzysztof Zygmunt Pac, the Chancellor of Lithuania. Michał Kazimierz Pac funded the construction of St. Peter and St. Paul Church in Vilna, considered to be one of the best examples of Baroque architecture in Lithuania. Following his wishes, he was interred in the church vestibule and his grave was marked with a Latin inscription Hic iacet pecator (English: Here lies a sinner).