Our Lady of Perpetual Help Parish was founded in 1919 by the first Bishop of Oklahoma, Theophile Meerschaert. Monsignor Monnot was appointed pastor on January 16, 1919 to a parish covering the 80 square miles that would serve the northward expansion of Oklahoma City. The first Masses in the new parish were celebrated in an automobile showroom on Classen Boulevard owned by the Rowe family. On May of 1919, twelve men worked for two days to build a temporary wooden church building on property purchased by the Parish... the property now bounded by NW 31st Streets, Western to Lake.
June of the same year was the groundbreaking ceremony for a permanent Church- School building. The first classes at Our Lady's School, taught by three Sisters of Mercy, were held on September 29th in a nearly completed building . Twelve grades were offered and ninety pupils enrolled the first year. The Sisters lived in the first Convent which was a two-story frame house across the street from the school.
After four years with Masses celebrated in the school, construction began on the church on July 3, 1923. In February of 1924 the last brick was laid on the stately campanile and the new Church was dedicated shortly thereafter.
A small wood frame Rectory was constructed in July of 1924 . Early in 1931, Pope Pius XI announced the elevation of the Church to position of the Cathedral Church of the Diocese. In 1932 the name of the school was changed to John Carroll in honor of the first Catholic Bishop of the United States.
In 1939 a new wing was added to the growing school and a new convent for the Sisters of Mercy was completed in 1941. Located on the corner of 31st and Lake, it is now called Mercy Center and is used for a variety of parish activities.
During the mid 1970's, Vietnamese refugees were leaving their homeland to escape the political unrest that was prevalent. Thirty Vietnamese families, seeking refuge from religious as well as political persecution in 1975 soon found their way to Our Lady's Cathedral and our Vietnamese population has been growing ever since.
In 1993, 75 years after the founding of the parish, "Renaissance" was begun. This complete restoration project included building a baptistery, replacing the original wiring and plumbing and installing new interior and exterior lighting. A new pipe organ, build by W. Zimmer and Sons of Charlotte, North Carolina, was installed also. Additional improvements included a new power plant, garage, gymnasium and classroom building for the parish school. Renovations are now complete for the Cathedral, school and grounds. A Cathedral Maintenance Endowment has been established for the future maintenance of the Cathedral facilities.