St. Mark's Cathedral is an Episcopal cathedral in Shreveport, Louisiana, United States. It is the seat of the Diocese of Western Louisiana. The first services of the Episcopal church in Shreveport were celebrated by the Rt. Rev. Leonidas Polk, the Bishop of Louisiana in March 1839. That liturgy is considered the founding day of St. Mark's Church. The parish church was located on the corner of Cotton Street and Texas Avenue since 1905. It is now the Church of the Holy Cross. Prior to that building, the church was located on Fannin Street. The present church at Fairfield Avenue and Rutherford Street was completed in 1954. It became the diocesan cathedral on July 7, 1990.