The Diocese of Tulsa is comprised of the following 31 counties in the eastern part of Oklahoma:
Adair, Atoka, Bryan, Cherokee, Choctaw, Coal, Craig, Creek, Delaware, Haskell, Hughes, Latimere, LeFlore, McCurtain, McIntosh, Mayes, Muskogee, Nowata, Okfuskee, Okmulgee, Osage, Ottawa, Pawnee, Payne, Pittsburg, Pushmataha, Rogers, Sequoyah, Tulsa, Wagoner and Washington.

There are 78 parishes and/or missions in the 26,417 square miles of the diocese.
A Diocese is a portion of the People of God, which is entrusted to a bishop to be nurtured by him with the cooperation of his priests (canon 369). The Diocesan Bishop enjoys legislative, executive, and juridical authority (canon 391). He is the chief pastor and leader of the diocese. He is the principal dispenser of the mysteries of God, and he strives constantly that Christ's faithful entrusted to his care may grow in grace through the celebration of the sacraments, and may know and live the paschal mystery (canon 387).