Jasper O'Farrell (1817–1875) was an Irish-American politician who served as the first surveyor for San Francisco.

[2] O'Farrell found work with the Mexican government and surveyed much of Marin and Sonoma counties.

O'Farrell improved the 1839 street maps produced by the former Mexican alcalde (mayor) of Yerba Buena, Francisco Guerrero, and his Swiss surveyor, Jean Jacques Vioget.

He was also influential in naming streets, including Market, Lombard, Chestnut, Filbert, and Pine.

O'Farrell named Valparaiso Street after the port in Chile, where he lived for a time before coming to San Francisco.