Victor Ramon Castro was the son of Francisco Maria Castro and Maria Gabriela Berreyessa y Peralta. Francisco's heirs were granted the 19,000-acre Rancho San Pablo in 1834. It was the first rancho established in the East Bay area, and extended from San Francisco Bay in El Cerrito south and eastward. Victor lived on the rancho and developed it, and eventually owned it.

In 1836, he married Maria Luisa Antonia Martinez Castro, who was born in Yerba Buena (later, San Francisco) in August of 1820 or 1822. She was the daughter of Maria Martina Guadalupe Arellanes and Lt. Ignacio Martinez, who served two terms as Commandante of the Presidio of San Francisco under Mexican rule, and later as Alcalde (Mayor) of San Francisco. The city of Martinez, California is named for him.

Maria and Victor lived at Rancho San Pablo and had seven children, three of whom died as children or teens. Maria died at age 30 or 32. Victor soon married again, wedding Maria Felicidad de las Angustias Carrillo y Lopez in 1853. She was known as Felicidad or Felicia Carrillo. They had a daughter, Jovita, who lived about 22 years. Felicia also bore a son, Victor, who died as an infant, shortly after his mother died. Victor married once more. In 1860, he married Julia Townsend Beardsley Lupton, who had come to California with her first husband in a covered wagon hoping to strike gold. Before their marriage, Julia worked for Victor as governess to his seven children. Julia and Victor had three boys and two girls, only one of whom lived beyond age 22. She was their youngest, Julia Bogart Castro.

In the 1840s, Victor started a ferry business across San Francisco Bay -- generally said to be the first of its kind. He was the grantee of the Isla de la Yegua (Mare Island) in San Francisco Bay with his brother Juan Jose, as well as the Rancho El Sobrante north and west of the San Pablo rancho. (Mare Island, named for an incident in which a Castro horse swam to the island from a passing barge, eventually would become the site of a major U.S. Naval base in the mid-twentieth century.) After California became a state in 1850, Castro family ownership of the land was confirmed by the California land commission in 1855 and by the District Court in 1858.

Victor was a local civic leader throughout his life. He was elected Supervisor in the new California county of Contra Costa in 1852. He had many friends in the arts.

Victor's father, Francisco, had come to the Bay Area as a small child on the De Anza expedition. Francisco's father, Joaquin Ysidro Castro, was a founder (original settler) of the cities of San Francisco and San Jose, California during the Spanish period.

Victor built one of the great private libraries of Old California in an era when so much great literature was being published and the Catholic Church was censoring it. As the priests worked to seize and destroy forbidden books arriving on ships reaching San Francisco, Victor and a couple of his friends arranged to off-load many of the books before the priests could find them. One of his friends was Mariano Guadalupe Vallejo, for whom the town of Vallejo, California (the state's original capital) was named, as well as the US Navy submarine USS Mariano G. Vallejo.

In 1900, the San Francisco Call reported:
BERKELEY. May 7.— Don Victor Castro was buried this morning in a plat on the Castro homestead. Rev. Father Riordan officiated at the funeral, which was private, only the relatives and closest friends of the family being present.
Don Castro was born at the Presidio in 1820 and when 16 years old erected the little adobe house in which he died. He obtained a grant of a large tract of land which extended from San Pablo to Oakland from the Mexican Government.
-San Francisco Call, Volume 87, Number 169, 8 May 1900, p. 8

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Victor's remains were reinterred in the 1950s to the Sunset View cemetery, along with several family members.