Demetrius Zvonimir (Croatian: Dmitar Zvonimir, pronounced [dmîtar zʋônimiːr]; Old Church Slavic: ⰸⱏⰲⱏⱀⰻⰿⰻⱃⱏ; died 1089) was a King of Croatia and Dalmatia from 1075 or 1076 until his death in 1089. Prior to that, Zvonimir also served as Ban of Croatia (1064/1070–1074). His native name was Zvonimir, but adopted the forename Demetrius at his coronation.
He first served as ban in the service of King Peter Krešimir IV. Afterwards, Peter Krešimir IV appointed him duke and declared him as his heir. In 1075 or 1076, Demetrius Zvonimir succeeded to the Croatian throne through papal diplomacy. His reign is characterized as relatively peaceful, with no extensive war campaigns, focused instead on Croatia's economic and cultural development.