Hillsborough is an incorporated town in San Mateo County, California, in the San Francisco Bay Area. Primarily a residential suburb of San Francisco, Hillsborough has many mansions and other points of interest within the town's borders dating from the early 20th century.

Hillsborough is an incorporated town in San Mateo County, California, in the San Francisco Bay Area. Primarily a residential suburb of San Francisco, Hillsborough has many mansions and other points of interest within the town’s borders dating from the early 20th century.