Ratimir, Duke of Lower Pannonia

Ratimir (Ratimarus) was a Croatian duke or prince (knez) that ruled the Duchy of Pannonian Croatia between ca. 829 to 838. His name contents the word "rat", meaning "war", and "mir", meaning "peace". It is believed that Ratimir descends from a royal dynasty that provided rulers for Moravia and Croatia.

In 827, the Bulgars under Great Khan Omurtag invaded and conquered the Croatian Principality of Southern Pannonia (Savia) and parts of Frankish territories to the north. In 829 the Bulgars imposed a local prince, Ratimir, as the new ruler of the territory. His province is believed to have been the territory of the former Roman Pannonia Savia, and is known in modern historiography as Lower Pannonia; earlier, Sigismund Calles (1750) called him "Slavic duke of the Drava".

In 838, nine years later, following the Bulgarian conquest of Macedonia, the Danubian count Radbod, prefect of the East March, deposed Ratimir and restored Frankish rule. Ratimir fled the land, and the Franks instated dukes Pribina and Kocelj to rule Pannonian area in the name of the Franks.

Unlike his predecessors, Ratimir experienced a rift in relations with the Christian Byzantine Empire.

According to the South Slavic Chronicle of the Priest of Duklja, rejected by historians, one of Ratimir's descendants was Svatopluk. According to modern Croatian historiography, Ratimir was a Croat prince.