Mill Valley is a city located in Marin County California. With a 2020 population of 14,185, it is the 336th largest city in California and the 2399th largest city in the United States . Mill Valley is currently declining at a rate of -0.26% annually but its population has increased by 2.03% since the most recent census, which recorded a population of 13,903 in 2010. Mill Valley reached it's highest population of 14,379 in 2014. Spanning over 5 miles, Mill Valley has a population density of 2,978 people per square mile.
The average household income in Mill Valley is $277,875 with a poverty rate of 5.57%. The median rental costs in recent years comes to $2,270 per month, and the median house value is $1.60 Mn. The median age in Mill Valley is 48.7 years, 48.3 years for males, and 48.9 years for females.