The Diocese of Pistoia is a Latin diocese of the Catholic Church located in the Province of Florence. It has existed since the third century. From 1653 to 1954, the historic diocese was the diocese of Pistoia and Prato. The Diocese of Prato has been separate from 1954. The diocese is a suffragan of the archdiocese of Florence.

The Archdiocese of Florence is a Latin Church metropolitan see of the Catholic Church in Italy. It was traditionally founded in the 1st century, according to the 14th century chronicler Giovanni Villani. The diocese was directly subordinate to the Holy See (Papacy) until 1420.