Guðnason is an Icelandic patronymic, meaning son of Guðni. In Icelandic names, the name is not strictly a surname because it is not a family name, but a patronymic. Notable people with this name include:
Guðni Ólafur Guðnason (b. 1965), Icelandic professional basketball player Haukur Ingi Guðnason (b. 1978), Icelandic professional football player Hilmir Snær Guðnason (b. 1969), Icelandic stage and film actor