Bulgarian Catholic Church
- Albanian Catholic Church
- Belarusian Catholic Church
- Bulgarian Byzantine Catholic Church
- Bulgarian Catholic Apostolic Exarchate of Sofia
- Bulgarian Catholic Apostolic Vicariate of Constantinople
- Bulgarian Catholic Apostolic Vicariate of Macedonia
- Bulgarian Catholic Apostolic Vicariate of Thrace
- Catholic Church in Bulgaria
- Croatian Catholic Church
- Greek Catholic Church
- Hungarian Catholic Church
- Romanian Catholic Church
- Russian Catholic Church
- Serbian Catholic Church
- Slovak Catholic Church
- Ukrainian Catholic Church