Old St. John's Hospital is an 11th-century hospital in Bruges, Belgium. Located next to the Church of Our Lady, it is one of Europe's oldest surviving hospital buildings. The hospital grew during the Middle Ages and was a place where sick pilgrims and travellers were cared for. The site was later expanded with the building of a monastery and convent. In the 19th century, further construction led to a hospital with eight wards around a central building.

Today part of the hospital complex holds the popular Hans Memling museum, named for the German-born Early Netherlandish painter, where a number of works, such as triptychs are displayed, as well as hospital records, medical instruments and other works of art.

The hospital site is also used as a congress and exhibition centre, the site Oud Sint-Jan.