Sancho I of Aragon (died 1094) was king of Aragon (1063-1094) and of Navarre (1076-1094) as Sancho V of Navarre. He was also called Sancho Ramirez.

He was the son of Ramiro I of Aragon and Ermesinde of Bigorre, and he succeeded his father Ramiro in 1063. He elected king of Navarre in 1076 after Sancho IV of Navarre died without an heir.

He conquered Barbastro in 1065, Graus in 1083, and Monzon in 1089.