The Church of St. Donatus is a church located in Zadar, Croatia. Its name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. Originally named (and dedicated to) the church of the Holy Trinity, in the 15th century it was renamed the Church of St. Donatus. Church of St. Donatus is the largest Pre-romanesque building in Croatia. It is also one of the most impressive churches of centralised type of the Carolingian period in Europe.