Seymour, WI has a population of 3,431 and is the 8,145th largest city in the United States. The population density is 1,275 per sq mi which is 1358% higher than the Wisconsin average and 1307% higher than the national average. The median age in Seymour is 36 which is approximately 8% lower than the Wisconsin average of 39. In Seymour, 63% of the population over 15 years of age are married, 98% speak English and 2% speak Spanish. 86% of Seymour residents were born in Wisconsin, 13% were born out of state, 1% were born outside of the United States and 0% were foreign born.