Germantown is an unincorporated community in O'Brien County, Iowa, United States. Germantown was platted on June 10, 1901. Edward D. Beerman did the platting. Germantown's population was 53 in 1902. It in the 1910s had a Christian school. The community was home to K-8th grade St. John Lutheran school, before it merged with Zion Lutheran …Germantown is an unincorporated community in O'Brien County, Iowa, United States. Germantown was platted on June 10, 1901. Edward D. Beerman did the platting. Germantown's population was 53 in 1902. It in the 1910s had a Christian school. The community was home to K-8th grade St. John Lutheran school, before it merged with Zion Lutheran School in Paullina to form Zion - St. John Lutheran School. By 1925, Germantown's population was 55.