Sancho IV (born c. 1038—died 1076, Peñalén, Navarre [Spain]) was the king of Pamplona (Navarre) from 1054 to 1076, son of García III (or IV).
Sancho had to contend with Castilian irredentism and Aragonese ambition. His act of persuading the Moorish king of Saragossa to become his vassal offended Alfonso VI of Castile, who invaded Pamplona (1074) and conspired with Sancho’s brothers and magnates to assassinate him at Peñalén. The kingdom of Pamplona was then occupied by Sancho Ramírez of Aragon, with Navarrese approval.