The Stuba Communis (Common Room) was built in the mid-15th century as the dining and meeting room for the inhabitants of Collegium Maius. Up until the 19th century, theology and senior liberal arts professors lived in the building. The scholars sat at three tables set in a U-formation according to the order of seniority. Following a monastic custom, the youngest professor would read the Bible and excerpts from the Church Fathers during each meal. Opposite to the tables is a Gothic oriel (the presbyterium of the former collegial chapel) with a wooden eagle-shaped lectern (16th c.) and a polychromy sculpture depicting Casimir the Great dating to ca. 1380. The figure was formerly located in a collegiate church in Wiślica.

The room is decorated with Baroque Gdańsk furniture made in the early 18th century: a spiral stairwell and a cupboard.

The Stuba Communis is the place for official meetings with important guests hosted by the University.