Euphemia of Sicily

Euphemia of Sicily (1330–1359) was a princess of the House of Barcelona, daughter of King Peter II of Sicily and Elisabeth of Carinthia. When her brother King Louis and her regent sister Constance both died of plague in 1355, the crown passed to her brother Frederick IV, and Euphemia was named vicar.

She ruled through feuds between rival noble factions, favouring one side until Frederick removed her from the vicariate, though she directed the regency until 1357. She never married and died in 1359.