Sancho II Garcés Abarca of Navarre was king of Navarre and count of Aragon from 970 to 994.

He was the son of García Sanchez I and Andregoto Galíndez, the daughter of Count Galindo II Aznárez of Aragon.

The Historia General de Navarra by Jaime del Burgo says –- referencing in turn the Anales del Reino de Navarra of José de Moret -- that on the occasion of the donation of the villa of Alastue by the king of Pamplona to the monastery of San Juan de la Peña in 987, he titled himself "King of Navarre," the first time that title had been used. In many places he appears as the first King of Aragon and in others the third.

During this period the kingdoms of Leon and Navarre and the County of Castile were united by familial bonds; the Navarrese monarchy supported the young Ramiro II of Leon .

Upon the death of Al-Hakam II in 976 and the succession of his son Hixem II , who had been taught by Almanzor, the prospects of the Christian kingdoms became even worse: the troops of Almanzor defeated the Christians at Torrevicente , south of Soria; afterwards they returned to triumph at Taracueña , near Osma .

In 975 Sancho was defeated by the Moors at San Esteban de Gormaz , and in 981 at Rueda, a dozen kilometers from Tordesillas , the Christians suffered another humiliating defeat.

Because he could not defeat Almanzor by arms, Sancho went to Córdoba as an ambassador for his own kingdom, bringing many gifts for the victorious Almanzor, making a pact with him and agreeing to give the Muslim his daughter in marriage. From this union was born Abd al-Rahman Sanchuelo , the heir to the Caliphate of Córdoba.

Sancho may have married Urraca Fernández of Castile in 962, the daughter of Ferdinand Gonzalez and Sancha of Pamplona. Before 950 Urraca had been married to Ordono III de Aza de Najera and in 956 she married the future Alphonso V "El Noble" de Leon , from whom she separated.

Children:

• García II Sanchez "the Trembling", King of Pamplona, who married Jimena Fernández
• Ramiro of Navarre (d. 992)
• Gonzalo of Navarre. Some documents list him as count of Aragon. He ruled together with his mother, Urraca, under the dependency of his father.
• Abda (Urraca) "the Basque" of Navarre, given to Almanzar before entering a convent. Larousse mentions Urraca Teresa of Navarre, married to Ramiro II of Leon and mother of Sancho I "the Crass" of León