St Catherine's Priory (Sankt Catharinæ Kloster) is a set of medieval monastic ruins in the centre of Roskilde, now forming part of the grounds of a secondary school. The Dominican priory was founded in the 13th century and was a significant centre of learning and religious life in medieval Denmark. The Reformation ended its religious function in 1537, and the buildings were subsequently repurposed, demolished in parts, and eventually absorbed into the school.
What survives is a section of the Gothic church and the cloister walks, which are accessible and give a reasonable impression of the priory's original scale. The ruins have a quiet, slightly overgrown quality that makes them more evocative than many better-preserved sites. The setting inside a working school adds to the sense that these are living parts of the city rather than museum exhibits.