The Church of St. John — officially the Church of St. Johns the Baptist and St. John the Apostle — stands within the Vilnius University complex and is the university's principal church. Originally a Gothic structure from the 14th century, it was comprehensively rebuilt in Baroque style between the 17th and 18th centuries by the Jesuits who ran the university. The result is one of the grandest Baroque interiors in Vilnius.
The bell tower, standing separately beside the church, is one of the tallest in the old town at 68 metres. It can be climbed and offers an excellent elevated view of the university courtyards and surrounding old town rooftops. The church interior has ten side chapels, each with Baroque altarpieces and sculptural programmes. Šv. Jono St. 12. Open Mon–Sat 10:00–17:00.