Chelsea, AL has a population of 11,706 and is the 3,484th largest city in the United States. The population density is 515 per sq mi which is 460% higher than the Alabama average and 468% higher than the national average. The median age in Chelsea is 34 which is approximately 12% lower than the Alabama average of 39. In Chelsea, 72% of the population over 15 years of age are married, 95% speak English and 2% speak Spanish. 61% of Chelsea residents were born in Alabama, 34% were born out of state, 2% were born outside of the United States and 3% were foreign born.