The Catholic Diocese of St. Augustine is a Roman Catholic diocese located in northeastern Florida. Established in 1565, it is the oldest diocese in the United States and serves a diverse population of Catholics across the region. The diocese is part of the larger United States Conference of Catholic Bishops and is dedicated to spiritual growth, education, and community service. The diocese encompasses several counties, including Duval, St. Johns, and Clay. Its headquarters is in the city of St. Augustine, which is known for its rich history and cultural heritage. The diocese operates numerous parishes, schools, and charitable organizations to support its mission.