The Diocese of Tucson was established by Pope Leo XIII on May 8, 1897.The diocese comprises nine counties in the state of Arizona, making it the fifth largest Roman Catholic diocese in the continental United States in terms of area. The diocese oversees 78 parishes, dozens of missions, 23 Catholic schools, and hundreds of charitable and fraternal organizations.The current Bishop of Tucson is Most Reverend Edward Weisenburger, who was appointed by His Holiness Pope Francis on October 3, 2017. The cathedral parish for the Diocese of Tucson is St. Augustine Cathedral.