An ecclesiastical region (Latin: regio ecclesiastica) is a formally organised geographical group of dioceses, ecclesiastical provinces or parishes, without a proper Ordinary as such, in Catholic or Protestant Churches.
Apart from historical other uses, there are presently ecclesiastical regions, grouping parts of the extensive episcopate in five Catholic countries.
The Catholic Church in Italy is divided into 16 ecclesiastical regions.
Fourteen of the regions (numbered I through XIV) are geographically based, for the Latin Catholic dioceses, the Eastern Catholic eparchies (dioceses) constitute the overlapping 'Region' XV.
Instead, it consists exclusively of US branches of various, generally Europe or Asia-based, particular Eastern Catholic Churches.