Lamoni is a city in Decatur County, Iowa, United States. The population was 2,444 at the 2000 census. Lamoni is the home of Graceland University, affiliated with the Community of Christ.

The town is a significant historic area for the Community of Christ church with the Liberty Hall museum. In 1870 a stewardship association of church members, known as the Order of Enoch, purchased over three thousand acres (12 km²) of land in southern Iowa as a place for gathering.

The city was named after Lamoni, a pacifist king mentioned in the Book of Mormon. Church headquarters relocated to the emerging community in 1881 and Joseph Smith III made Liberty Hall his home. Four Community of Christ church presidents lived in Liberty Hall. The church was headquartered in Lamoni, Iowa, and Liberty Hall was a center of social and religious life for the community. During the next 60 years, Liberty Hall served as a home for the aged, a farmhouse, CCC Headquarters, and a private residence. Now restored to its 1900-1905 Victorian style, Liberty Hall reflects the culture of the large, middle class Smith family living in a small, mid-western town as well as the heritage of Community of Christ. Tours are available March through December.

Lamoni was named to the list of "Best 100 cities for Young People" in the nation by Americas Promise http://www.americaspromise.org/100Best/winning_communities.cfm

Among the significant structures in Lamoni are the Roy A. Cheville Chapel, Closson Physical Education Center, Shaw Center for the Performing Arts, Frederick Madison Smith Library, and the Higdon Administration Building, all on the Graceland University Campus.

Recently, the Lamoni area has also become home to a sizable Amish community.