Fernando (or Fernán) Pérez de Traba (c.1090–1 November 1155), also Fernão Peres de Trava ([fɨɾˈnɐ̃w̃ ˈpeɾɨʒ dɨ ˈtɾavɐ] or [ˈtɾavə]) in Portuguese, was a nobleman and count of the Kingdom of León who for a time held power over all Galicia. He became the lover of Countess Teresa of Portugal, through whom he attained great influence in that domain, and was the de facto ruler of the County of Portugal between 1121 and 1128. The Poema de Almería, a Latin poem celebrating one of Alfonso VII's major victories of the Reconquista, records that "if one were to see him [Fernán], one would judge him already a king."
Fernán was the second son of Pedro Fróilaz de Traba, founder of the House of Traba, and his first wife, Urraca Fróilaz. His family was the most powerful in Galicia at the time, and he himself held properties in the most important Galician cities: Lugo and Santiago de Compostela. Fernán's first appearance in the surviving documentation dates from September 1107, just after the death of Raymond of Galicia, when his father confirmed a privilege of Alfonso VI for the monastery of Caaveiro, along with his sons.