Tun Tavern was a tavern in Philadelphia, Pennsylvania which served as a founding or early meeting place for a number of notable groups. It is traditionally regarded as the site where the United States Marine Corps held its first recruitment drive. It is also regarded as the "birthplace of Masonic teachings in America."

Samuel Carpenter and his brother Joshua erected the tavern beginning in 1685 at the intersection of King (later called Water) Street and Tun Alley. Tun Tavern was named for the Old English word "tun", meaning a barrel or keg of beer. In the 1740s, a restaurant, "Peggy Mullan's Red Hot Beef Steak Club", was added to the tavern.

Tun Tavern hosted the first meetings of a number of organizations. In 1720, the first meetings of the St. George's Society (forerunner of today's "Sons of the Society of St. George") were held there. The Society was a charitable organization founded to assist needy Englishmen arriving in the new colony. In 1732, the tavern hosted St. John's No. 1 Lodge of the Grand Lodge of the Masonic Temple in its first meetings. (The Masonic Temple of Philadelphia recognizes Tun Tavern as the birthplace of Masonic teachings in America.) In 1747, it became the founding point of the St. Andrew's Society, which, similarly to the St. George's Society, aided newly arriving Scottish.