Burgo de Osma-Ciudad de Osma is the third-largest municipality in the province of Soria, in the autonomous community of Castile and León, Spain. It has a population of about 5,250.

It is made up of two parts:

• the smaller Ciudad de Osma (city of Osma) to the west of the river Ucero, which flows southwards to the river Duero; and
• the larger El Burgo de Osma (the borough of Osma, sometimes just called El Burgo) to the east of the river Ucero, the cathedral town of the province.
• Osma derives from the Celto-Roman Uxama, while Burgo is cognate to the English word borough.

The Cathedral of Burgo de Osma is a Roman Catholic church located in central Spain. It is in the Gothic architectural style, and was constructed on an area previously occupied by a Romanesque church. It is one of the best preserved medieval buildings in the country and considered one of the best examples of thirteenth-century gothic architecture in Spain. The building of the church started in 1232, and was completed in 1784. The cloister is from 1512. The tower is from 1739. The cathedral is dedicated to the Assumption of Mary. It is the seat of the Bishop of Osma.