San Mateo County, California has been identified as the wealthiest county in America based on average household income and typical home value. According to data from the 2022 American Community Survey and Zillow's 2024 typical home value, San Mateo County has an average household income of $216,684 and a typical home value of $1,702,429. Marin County, California and Santa Clara County, California rank second and third on the list. The state of Virginia has the highest concentration of wealthy counties, with a total of nine counties making the list. This ranking provides insight into the economic prosperity and high property values in these areas. [b883ee33]