Sancho ISancho I may refer to: Sancho I of Gascony, Basque Duke Sancho I of Pamplona, Navarrese monarch Sancho I Ordóñez, King of Galicia Sancho I of León, two-time King of León Sancho I of Aragon, second king of Aragon Sancho I of Astarac, count of Astarac Sancho I of Portugal, King of Portugal