Petaluma, CA has a population of 59,757 and is the 651st largest city in the United States. The population density is 4,155 per sq mi which is 1688% higher than the California average and 4486% higher than the national average. The median age in Petaluma is 42 which is approximately 16% higher than the California average of 36. In Petaluma, 57% of the population over 15 years of age are married, 75% speak English and 17% speak Spanish. 59% of Petaluma residents were born in California, 22% were born out of state, 1% were born outside of the United States and 18% were foreign born.