García Sánchez (died 1029) was the last independent count of Castile from 1017 to his death. Son of Sancho García and his wife Urraca, he succeeded his father when he was only a boy.
During his minority the post of regent was held by several Castilian magnates and Urraca, Abbess of Covarrubias, the young count's aunt. The county fell under the protection of his brother-in-law, King Sancho III of Pamplona (Sancho the Great). His sister, Jimena, was married to Bermudo III of León.
He reached his majority in 1028. He was assassinated the next year when leaving the royal palace in León by the brothers Rodrigo Vela and Íñigo Vela. He had gone there to meet his fiancée, Infanta Sancha, sister of Bermudo III of León,
The countship was assigned to his nephew Ferdinand, younger son of his sister Muniadona and her husband Sancho the Great.