Hroðgar (Proto-Norse *Hrōþigaizaz [1], Hrothgar, Hróar, Ro), legendary Danish king.

According to the epic poem Beowulf, he ruled Denmark when the Geatish hero Beowulf arrived to defeat the monster Grendel and he was married to Wealhþeow. He was supposed to have built a famous hall called Heorot, and according to Saxo Grammaticus in Gesta Danorum, he (Roar or Ro) founded the town Roskilde. His brother Halga (Helgi) who ruled before him had a famous son, Hrothulf (Hrólf Kraki).

See also Origins for Beowulf and Hrólf Kraki for more on the historical background of these characters.

Hrothgar is also the name of the dwarven king in the newly published book Eragon, by Christopher Paolini. Hrothgar, from Beowulf, is the source of the dwarf's name.