| Date | Country | Change |
| 1854 | Diocese of Brugnato lost territory to Diocese of Massa Carrara | |
| 1854 | Diocese of Luni–Sarzana lost territory to Diocese of Massa Carrara | |
| 1854.03.08 | Apostolic Vicariate of Poona was established (from Apostolic Vicariate of Bombay) | |
| 1854.06.06 | Diocese of Ceará was established (from Diocese of Olinda and became suffragan of São Salvador da Bahia) | |
| 1854.06.06 | Diocese of Diamantina was established (from Metropolitan Archdiocese of São Salvador da Bahia, Diocese of Mariana and Diocese of Olinda and became suffragan of São Salvador da Bahia) | |
| 1854.08.31 | Diocese of San Luis Potosí was established (from Metropolitan Archdiocese of México, Diocese of Guadalajara and Diocese of Michoacán and became suffragan of México) | |
| 1854.11.16 | Metropolitan Archdiocese of Făgăraş (Romanian Rite) was promoted as Metropolitanate sui juris of Făgăraş şi Alba Iulia | |
| 1854.11.30 | Diocese of Sant’Agata de’ Goti lost territory to Diocese of Acerra |
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