A group of several Lutheran families gathered at Anson Park Shelter House on October 1, 1975 to determine if there was enough interest to form a new Lutheran church in Marshalltown. A week later, members of 27 families signed a sheet pledging them to starting Our Savior Lutheran Church. The first Sunday worship service was October 12, 1975 at the Salvation Army Citadel, 107 W. State St.

Several guest pastors were used the first few Sundays until the Rev. Paul Discher accepted the call of Our Savior to he the pastor on a half-time basis. Worship services were held of the Salvation Army until October 3, 1976, when the congregation rented part of a new office building of 202 West State St., the current site of the local Social Security office. Pastor Discher resigned in June 1977 and on October 2 the Rev. Dennis Bauer was installed as the first full-time pastor of Our Savior Lutheran Church. In 1978 the congregation became affiliated with the Association of Evangelical Lutheran Churches (AELC).

In April 1978 the congregation purchased a six-acre tract of land on South Sixth Street. Worship services were moved to the First Congregational Church in September 1979 and continued there until December 7, 1980 when a newly constructed 3,700 square foot building on the South Sixth Street property costing $100,000 was used for the first time. Pastor Bauer continued to serve the congregation until his resignation in 1983. The Rev. Dwight Wascom was called and was installed as Pastor of Our Savior Lutheran Church on December 11, 1983.

A six-room education unit costing $65,000 was put to use March 10, 1985. Our Savior became a part of the Evangelical Lutheran Church of America (ELCA) in 1988. PastorWascom resigned in 1989 and was replaced by the Rev. Allan Thoreson.

A new worship center was built for $350,000 in 1996-97 and the new facility was dedicated on Palm Sunday, March 23, 1997. Pastor Thoreson retired on March 30, 1997 and was replaced by the Rev. Dr. William Spencer who led worship services for the first time on May 24, 1998.

The congregation celebrated its 25th anniversary in October 2000 with several special services.