Union Sportive Pays de Saint-Omer (USPSO) is a French association football team founded in 1894.

As of the 2022–23 season, they play in the sixth tier in the French football league system.

The team was known as Union Sportive de Saint-Omer until 2020, when a merger with FC Tatinghem took place, and the name Union Sportive Pays de Saint-Omer was taken.

[2] Their best-ever performance in the French Cup saw them reach the last 16 in season 1991–92 before losing 2–4 to AS Monaco at home.

In season 2008–09, they knocked SC Amiens (a Ligue 2 side) out of the same competition in the seventh round.