Many People ask: Where is Nauvoo, Illinois. For those traveling to Nauvoo it can be a journey to get there. Nauvoo is a small city in Hancock County, Illinois. It is located right on the Mississippi River across from Fort Madison, Iowa. Those asking where Nauvoo is are usually those visiting Nauvoo for its historic importance and its religious significance to members of several groups: The Church of Jesus Christ of Latter-day Saints, the Community of Christ, formerly the Reorganized Church of Jesus Christ of Latter Day Saints (RLDS); other groups stemming from the Latter Day Saint movement; and the Icarians. The city and its immediate surrounding area are listed on the National Register of Historic Places as the Nauvoo Historic District.