Guiscarda (or Guiscarde) (died 1154) was the ruling Viscountess of Béarn in 1134, and acted as regent during the minority of her son in 1134-1147, as well as for her grandson in 1153-1154. She was the eldest child of Gaston IV of Béarn and Talesa of Aragon. She later succeeded her younger brother Centule VI as viscountess in 1134, but left the post to her son. As her son was a minor, however, she nevertheless acted as regent until 1147. When Peter died in 1153, Guiscarda assumed the regency for his son Gaston V, until her own death the next year.