Jerome, ID has a population of 11,140 and is the 3,628th largest city in the United States. The population density is 1,998 per sq mi which is 10370% higher than the Idaho average and 2105% higher than the national average. The median age in Jerome is 28 which is approximately 21% lower than the Idaho average of 36. In Jerome, 64% of the population over 15 years of age are married, 72% speak English and 27% speak Spanish. 55% of Jerome residents were born in Idaho, 28% were born out of state, 0% were born outside of the United States and 16% were foreign born.