San Anselmo is a city located in Marin County, California. With a 2020 population of 12,411, it is the 354th largest city in California and the 2649th largest city in the United States. San Anselmo is currently declining at a rate of -0.43% annually but its population has increased by 0.61% since the most recent census, which recorded a population of 12,336 in 2010. San Anselmo reached it's highest population of 13,031 in 1970. Spanning over 3 miles, San Anselmo has a population density of 4,636 people per square mile.
The average household income in San Anselmo is $169,545 with a poverty rate of 3.70%. The median rental costs in recent years comes to $1,798 per month, and the median house value is $1.04 Mn. The median age in San Anselmo is 47.9 years, 47.3 years for males, and 48.9 years for females. For every 100 females there are 89.9 males.