Sebastopol, CA has a population of 7,630 and is the 4,870th largest city in the United States. The population density is 4,102 per sq mi which is 1665% higher than the California average and 4427% higher than the national average. The median age in Sebastopol is 48 which is approximately 34% higher than the California average of 36. In Sebastopol, 48% of the population over 15 years of age are married, 87% speak English and 8% speak Spanish. 59% of Sebastopol residents were born in California, 28% were born out of state, 2% were born outside of the United States and 11% were foreign born.