The Cathedral of Our Lady of Perpetual Help is a Catholic cathedral in Oklahoma City, Oklahoma, United States. It is the seat of the Archdiocese of Oklahoma City. Our Lady of Perpetual Help Parish was established in 1919 when Bishop Theophile Meerschaert, the first Bishop of Oklahoma City, assigned Monsignor Monnot its first pastor on January 19. Mass for the parish was initially celebrated in an automobile showroom on Classen Boulevard. The first church building was a wood structure built in May 1919 on NW 31st Street between Western and Lake.
The following month a ground breaking was held for a combination church and school building. Construction of the present church building was begun on July 3, 1923 and it was completed in February 1924. A frame rectory was completed in July of the same year. Pope Pius XI elevated Our Lady of Perpetual Help to a cathedral in 1931. It replaced St. Joseph Cathedral downtown.