Name History

According to the heraldic scholars, the Garcia Carraffa Brothers, the Spanish surname O originated in the mountains of Leon. From there, a member of this family moved to Avila, where he established a "casa solar" or ancient family seat. The surname O is of toponymic origin, being derived from the place of residence of the original bearer.
In this case, the surname derives from the Marquisate of O, lands which were first granted to this family in 1677; the title Marquis of O has been held by Don Joaquin Cabrera Trillo Figueroa since 1916. Thus the surname O signifies "one from O".
The place name derives from the Basque word "ote, ota" meaning "stack, vine" and Latin word "verus" meaning "true, real, genuine".

References to the surname O include one Isabela de O, as registered in the Index of Noble Surnames of the Order of Carlos III, a Spanish military order. At the same time, this surname was established on the American continent in areas where the Spanish influence was most notable in the sixteenth century. Isabel de O is mentioned in "Americans in the Orders of Nobility"; she was married to Don Juan de Torre Luna, "Alcalde Ordinario" of San Sabastian de Leon in 1687. In the index of the personal expenditures of the "Archivo General Militar de Segovia" are registered some bearers of the name who served in the ranks of the Royal Army of Spain. Among them were: Jose O - nobleman, who served in the Artillery Regiment in 1796; Antonio O Ruiz of the Volunteer Battalion in 1896, and Pascual O Medrano, also of the Volunteers in 1822. Listed in the "Biographical Index of Spain, Portugal and Latin America" was the Spanish writer, professor and veterinarian, in the year 1814.

Also know that there were two sets of O' that came across the Atlantic in the 1500's. The first ones stopped into Mexico after Cortez and remained there. These are the O' from Mexico. The second wave stayed on the boat around the horn to Spanish California. These are the Californian O'.