Deerfield, WI has a population of 2,488 and is the 9,887th largest city in the United States. The population density is 1,150 per sq mi which is 1215% higher than the Wisconsin average and 1169% higher than the national average. The median age in Deerfield is 36 which is approximately 8% lower than the Wisconsin average of 39. In Deerfield, 60% of the population over 15 years of age are married, 96% speak English and 3% speak Spanish. 81% of Deerfield residents were born in Wisconsin, 17% were born out of state, 1% were born outside of the United States and 1% were foreign born.