Piotr Pac (after 1570-1642) was a Polish-Lithuanian noble, Lithuanian Court Chorąży from 1613, Lithuanian Court Treasurer from 1635, Voivode of Trakai (1640-1642).
He took part in the Battle of Kircholm in 1605. In 1607 he took part in the commission setting borders between the Polish-Lithuanian Commonwealth and Duchy of Courland.