Ermesinde of Carcassonne, countess and regent of Barcelona (b. 972)
Ermesinde of Carcassonne (ca. 975/8 – 1 March 1058) was Countess consort of Barcelona, Girona and Osona. She served as regent in these counties during the minority of her son from 1018 until 1023.

Ermesinde of Carcassonne was the daughter of Roger I of Carcassonne. She married Ramon Borrell, Count of Barcelona.While he lived she was politically active and presided over assemblies and tribunals. After his death in 1018 she became regent for her son Berenguer Ramon I until 1023. After this, she continued to wield power. Her patronage and close relationship with the Catholic Church helped her build an influential entourage of church officials who helped her retain power throughout her life. In contrast to her son, she favored war with the Muslim powers to the South, partly because of the discontent of the nobles at his policy of peace. When he died in 1035, she became regent for her grandson until he was declared to be of age in 1044.