Fortún Ochoiz or Fortún Ochoa (floruit 1013–1050) was a Navarrese nobleman, diplomat, and statesman. Throughout his known career he held the tenencia of La Rioja, an important marcher lordship, the rump of the Kingdom of Viguera, and the foundation for the Lordship of Los Cameros. Fortún helped fix the border between southwestern Navarre and the Kingdom of Castile, and he married into the royal family and fought alongside his father-in-law, García Sánchez III in the Reconquista. His ancestors may have belonged to the Banu Qasi, themselves descended from Visigothic nobility, and his descendants continued to rule their patrimony until the twelfth century.