Santos Hildebrando Rivas García was born in Chalatenango, Chalatenango Department, El Salvador, on 17 August 1911. His parents were Catarino Rivas and María Inéz García. He had two siblings, a brother with the same name who died at the age of 1 in 1910, and a younger sister named Genara, born in 1913. According to his family, his father has Spanish ancestry.

On 20 May 1933, he married Rosalina Alas Rivera in his hometown. He had 2 children before marriage, and 13 more legitimate children with Rosalina.

During his life, he lived in 4 cities in El Salvador: Chalatenango (his birthplace), La Ceiba, Jujutla and San Pablo Tacachico. He lived in Guatemala for around 5 years (for some or all the time in the city of Tiquisate). He was part of El Salvadoran national mail on foot correspondence from San Salvador to Nueva Ocotepeque (Honduras) from 1934 to 1956. He was a carpenter by profession and knew how to make hammocks and various other crafts. He was a farmer for over 80 years. He never received a pension. According to his relatives, his diet was normal, he never had a specific diet.

Rivas García passed away in San Pablo Tacachico, La Libertad, El Salvador, on 17 April 2023, at the age of 111.