Rev. Theodore Julius Christian Stellhorn was born in Watertown, Wisconsin. He was the son (and later would be the father of) a Lutheran minister. The Stellhorn family moved to Fort Wayne, Indiana, where the father of the family was a professor at Concordia College. Next, the Stellhorns moved to Columbus, Ohio, where Rev. Theodore J.C. Stellhorn attended Capital University. He graduated in 1889, and three years later he became a graduate of the Divinity School at Capital.
In June of 1892 Rev. Stellhorn became the pastor of a newly organized church in Fort Wayne. He came to Sandusky in November, 1897, to become an assistant to his brother in law, Dr. August Dornbirer. In 1907, Rev. Theodore J.C. Stellhorn was called to become the pastor of Zion Lutheran Church in Sandusky.
Rev. Stellhorn helped to organize Lutheran churches in Castalia, Huron, and Venice, Ohio. From 1928 ti 1948, Dr. Theodore J.C. Stellhorn and Rev. Theodore Stellhorn, Jr. worked together at Zion Lutheran Church, the being the assistant pastor, and the elder Rev. Stellhorn serving as the head pastor. In 1948, Dr. Theodore J.C. Stellhorn was advised by his doctors not to preach at public worship services any longer, so the senior paster visited the sick and shut-ins of the community, and continued to serve on several church committees.
On February 18, 1955, Rev. Theodore J.C. Stellhorn died at at the age of 83. He was buried at Oakland Cemetery with his wife Katherine. Officiating at the funeral of Dr. Stellhorn was: Rev. Maurice White, of Lima; Rev. David Wolber, assistant pastor at Zion; Rev. J.A. Griffith, of St. Paul's Lutheran Church; and Rev. John Braun, pastor of St. John's Lutheran Church in Port Clinton, and formerly of Trinity Lutheran at Venice.
An obituary for Rev. Stellhorn appeared on the front page of the February 18, 1955 issue of the Sandusky Register Star News. The article reported that Dr. Stellhorn was one of the most able leaders of Lutherans on the Sandusky area. Rev. Stellhorn was survived by his son, Rev. Theodore Stellhorn, Jr., two daughters, and several grandchildren and great grandchildren. One son, Luther, had died in 1954, and his wife, the former Katherine Dornbirer died in 1951.