lthough he played many different ethnicities in his acting career, Leo Carrillo was Castillian Spanish and traced his ancestry in Spain to the year 1260. His great-great grandfather José Raimundo Carrillo (1749–1809), was a soldier in the Spanish Portolá expedition colonization of Las Californias, arriving in San Diego on July 1, 1769. Franciscan Friar Junípero Serra performed the marriage ceremony for Don Jose Raimundo and Tomasa Ignacia Lugo in 1781. His great-grandfather Carlos Antonio Carrillo (1783–1852) was Governor of Alta California (1837–38). His great-uncle, José Antonio Carrillo, was a three-time mayor of Los Angeles and twice married to sisters of Governor Pío Pico. His paternal grandfather, Pedro Carrillo, who was educated in Boston, was a writer. The family moved from San Diego to Los Angeles then to Santa Monica, where Leo Carrillo’s father Juan José Carrillo (1842–1916), served as the city’s police chief and later the first mayor. His cousin was Broadway star William Gaxton (real name Arturo Antonio Gaxiola). Proud of his heritage, Carrillo wrote a book, The California I Love, published shortly before his death in 1961. A university graduate, Carrillo worked as a newspaper cartoonist for the San Francisco Examiner before turning to acting on Broadway. In Hollywood, he appeared in more than 90 films, including The Gay Desperado (1936), in which he usually played supporting or character roles.

However, Leo Carrillo is best remembered from the television series The Cisco Kid, on which, beginning at the age of seventy, he portrayed the sidekick Pancho, a role that he had previously played in several films. Duncan Renaldo (1904–1980) starred as The Cisco Kid. The popular syndicated series ran from 1950 until 1956, notable as the first TV series filmed in color. After The Cisco Kid ended production, Carrillo appeared in the episode “Rescue at Sea” of the syndicated military drama, Men of Annapolis. In 1913, Carrillo married Edith Shakespeare Haeselbarth, of Nyack, New York, whom he met backstage at the New York City theater where she had seen him perform. They remained together until her death in 1953. They lived in “Los Alisos” (“The Sycamores”) on Channel Road, in Santa Monica Canyon. The Carrillos had one child, a daughter, Marie Antoinette. They spent part of their time at their 4,500-acre (1,800 ha) ranch in Carlsbad. Carrillo frequently permitted Boy Scout groups to camp on the grounds. Leo Carrillo died of cancer in 1961 at the age of eighty-one and is interred at Santa Monica’s Woodlawn Memorial Cemetery.