The Roman Catholic Diocese of Las Cruces (Latin: Dioecesis Las Cruces) is an ecclesiastical territory or diocese of the Roman Catholic Church in the southwestern region of the United States, comprising the 10 southern counties in the state of New Mexico: Hidalgo, Grant, Luna, Sierra, Doña Ana, Otero, Lincoln, Chaves, Eddy, and Lea. It is led by a prelate bishop which serves as pastor of the motherchurch, Cathedral of the Immaculate Heart of Mary, in the City of Las Cruces. Its congregants are overwhelmingly Hispanic, mostly Mexican in descent. The diocese is a suffragan see of the Archdiocese of Santa Fe.