The following dioceses have seminarians in formation at St. John Vianney Theological Seminary:

Archdiocese of Denver
Diocese of Bismarck
Diocese of Dodge City
Diocese of Gallup
Diocese of Helena
Archdiocese of Kansas City – Kansas
Archdiocese of Oklahoma City
Diocese of Phoenix
Diocese of Pueblo
Diocese of Salina
Diocese of Bui Chu, Vietnam
Diocese of Kasana-Luweero, Uganda
Diocese of Tarawa and Nauru, Kiribati
Archdiocese of Yangon, Myanmar