Saint-Ursanne is an old town and a former municipality of the district of Porrentruy in the Canton of Jura , Switzerland which has preserved much of its medieval character. The town contains many historical buildings, including a Romanesque abbey church, a collegiate church, a cloister, many medieval houses, a hermitage and an 18th-century bridge. The river Doubs makes a loop near Saint-Ursanne before flowing into France. Since 2009 Saint-Ursanne has been a part of the new municipality Clos du Doubs. An active railway station is located above the town, to the east.

The town is famous for the medieval festival which it organizes each summer, and for the annual St-Ursanne–Les Rangiers International Hill Climb in August.