High Quality Content by WIKIPEDIA articles! Oelwein is a city in Fayette County, Iowa, United States. The population was 6,692 at the 2000 census. The largest community in Fayette County, it is located at the junction of State Highways 3 and 150. As of the census of 2000, there were 6,692 people, 2,808 households, and 1,819 families residing in the city. The population density was 1,395.8 people per square mile (539.4/km²). There were 3,040 housing units at an average density of 634.1/sq mi (245.0/km²). The racial makeup of the city was 97.19% White, 0.42% African American, 0.19% Native American, 0.40% Asian, 0.06% Pacific Islander, 0.64% from other races, and 1.09% from two or more races. Hispanic or Latino of any race were 2.29% of the population.