Episcopal services were inaugurated in Tullahoma in 1867 by the Reverend Harvey O. Judd, Deacon. The small congregation was formally organized as the Mission of the Incarnation. St. Barnabas associated with the Diocese as a Parish in January, 1874 and soon became the center for mission work in the area.

The first church building, a frame structure, was consecrated in 1874. In 1897 it was replaced with the present larger edifice, a Gothic Revival design of architect R.H. Hunt.

For many years the interior walls were covered with plaster and a walnut wainscot. Repair work begun in 1966 required the removal of the plaster and wainscoting and revealed the brick seen today.

The church is noteworthy for its fine (and growing collection of) stained glass windows, all dating since 1964 with the exception of the two circular windows, which may date to the turn of the century.