Portola Valley is an incorporated town in San Mateo County, California, United States. It was named for Spanish explorer Gaspar de Portolá, who led the first party of Europeans to explore the San Francisco Peninsula in 1769. The population was 4,353 at the 2010 census.

Portola Valley is one of the forty wealthiest towns in the United States, with a median household income of $244,771 a year. Within the State of California, Portola Valley is ranked as the sixth wealthiest place. The zip code 94028, which encompasses the whole of Portola Valley, has the 9th most expensive housing prices within the country according to Forbes Magazine 2013.[4]