Date | Country | Change |
| 1401.03.08 |  Italy | Abbacy nullius of San Cristoforo di Castel Durante was established (from Diocese of Urbino) |
| 1403.07.04 |  Portugal | Diocese of Guarda lost territory to Diocese of Lamego |
| 1403.07.04 |  Spain | Diocese of Ciudad Rodrigo lost territory to Diocese of Lamego |
| 1404 |  Ukraine | Diocese of Luceoria was established (from Diocese of Lodomeria) |
| 1404.07.07 | Spain | Diocese of Rubicón was established (from Diocese of Telde and became suffragan of Sevilla) |
| 1410 | Italy | Diocese of Fiorentino was suppressed (to Diocese of Lucera) |
| 1412 |  France | Diocese of Sospel was suppressed (to Diocese of Ventimiglia) |
| 1413.01.13 | Italy | Abbacy nullius of Nardò was promoted as Diocese of Nardò (without ecclesiastical province) |
| 1414.12.24 | Ukraine | Metropolitan Archdiocese of Halyč was suppressed (to Metropolitan Archdiocese of Lviv) |
| 1414.12.24 | Ukraine | Diocese of Lviv was promoted as Metropolitan Archdiocese of Lviv (with suffragan sees Chełm, Kamyanets-Podilskyi, Kyiv, Lodomeria, Przemyśl and Siret and gained territory from the suppressed Metropolitan Archdiocese of Halyč) |
| 1417.04.04 | Spain | Diocese of Ceuta was established (from Diocese of Marocco and became suffragan of Lisboa) |
| 1417.10.24 |  Lithuania | Diocese of Žemaitija was established (became suffragan of Gniezno) |
| 1418 |  Romania | Diocese of Baia was established |
| 1418 | Romania | Diocese of Moldovita was established |
| 1419.05.10 | Italy | Diocese of Firenze was promoted as Metropolitan Archdiocese of Firenze (with suffragan sees Fiesole and Pistoia) |
| 1420.02.12 | Italy | Diocese of Suelli was suppressed (to Metropolitan Archdiocese of Cagliari) |
| 1421 | Spain | Diocese of Tui lost territory to Diocese of Ceuta |
| 1422.10.19 | Italy | Diocese of Ancona was renamed as Diocese of Ancona e Umana (gained territory from the suppressed Diocese of Numana) |
| 1422.10.19 | Italy | Diocese of Numana was suppressed (to Diocese of Ancona e Umana) |
| 1424 | Italy | Diocese of Salpi was suppressed (to Metropolitan Archdiocese of Trani) |
| 1424.10.17 |  Poland | Diocese of Kraków lost territory to Diocese of Chełm |
| 1424.11.20 | Spain | Diocese of Fuerteventura was established (from Diocese of Rubicón and became suffragan of Sevilla) |
| 1425 | Italy | Territorial Abbacy of San Paolo fuori le Mura was established |
| 1425 | Italy | Diocese of Tortiboli was suppressed (to Diocese of Lucera) |
| 1425 |  Morocco | Diocese of Marocco was suppressed |
| 1425.12.19 | Ukraine | Diocese of Lodomeria was suppressed (to Diocese of Luck and Włodzimierz) |
| 1425.12.19 | Ukraine | Diocese of Luceoria was renamed as Diocese of Luck and Włodzimierz (gained territory from the suppressed Diocese of Lodomeria and became suffragan of Lviv) |
| 1426 | Italy | Diocese of Valva lost territory to Diocese of L’Aquila |
| 1426.06.21 | Poland | Diocese of Chełm lost territory to Diocese of Kraków |
| 1428 |  Ireland | Diocese of Mayo was restored (from Metropolitan Archdiocese of Tuam) |
| 1429 | Ireland | Diocese of Cloyne was suppressed (to Diocese of Cork and Cloyne) |
| 1429 | Ireland | Diocese of Cork was renamed as Diocese of Cork and Cloyne (gained territory from the suppressed Diocese of Cloyne) |
| 1429 | Italy | Diocese of Nuceria was renamed as Diocese of Nocera de’ Pagani |
| 1429 |  Serbia | Diocese of Graeca Alba was renamed as Diocese of Beograd (became suffragan of Kalocsa) |
| 1430 |  Israel | Titular Episcopal See of Nicopoli di Palestina was established |
| 1430 | Italy | Metropolitan Archdiocese of Pisa lost territory to Metropolitan Archdiocese of Genova |
| 1432 |  Greece | Diocese of Oleno was suppressed |
| 1433 | Spain | Diocese of Fuerteventura was suppressed (to Diocese of Rubicón) |
| 1434 | Romania | Diocese of Siret was suppressed (to Diocese of Baia) |
| 1435.12.05 | Italy | Diocese of Corneto was restored (from Diocese of Tuscanella) |
| 1437 | Spain | Titular Episcopal See of Granada was established (from former Diocese of Elvira) |
| 1437.03.20 | Italy | Diocese of Cariati was established (from Archdiocese of Rossano and became suffragan of Santa Severina) |
| 1439.07.29 | Ireland | Diocese of Connor was suppressed (to Diocese of Down) |
| 1440 | Greece | Metropolitan Archdiocese of Thebæ was suppressed |
| 1440 | Italy | Diocese of Eraclea was suppressed (to Patriarchal See of Grado) |
| 1441 | Italy | Metropolitan Archdiocese of Torres was renamed as Metropolitan Archdiocese of Sassari |
| 1441 | Spain | Diocese of Telde was suppressed |
| 1442 |  Northern Ireland | Diocese of Down was renamed as Diocese of Down and Connor |
| 1442 | Spain | Diocese of Orihuela was established (from Diocese of Cartagena) |
| 1443.10.11 | Spain | Diocese of Orihuela was suppressed (to Diocese of Cartagena) |
| 1449 | Italy | Archpresbyterate nullius of Lanciano was established (from Diocese of Chieti) |
| 1450 |  Algeria | Titular Episcopal See of Thagaste was restored |
| 1450 | Greece | Diocese of Daulis was suppressed |
| 1450 |  India | Diocese of Quilon was suppressed |
| 1450 |  Iran | Metropolitan Archdiocese of Soltania was suppressed |
| 1450 |  Lebanon | Diocese of Ehden (Maronite Rite) was established |
| 1451 | Greece | Diocese of Nisyros was suppressed |
| 1451.10.08 | Italy | Diocese of Castello was suppressed (to establish Patriarchal See of Venezia) |
| 1451.10.08 | Italy | Patriarchal See of Grado was suppressed (to establish Patriarchal See of Venezia) |
| 1451.10.08 | Italy | Patriarchal See of Venezia was established (from the suppressed Patriarchal See of Grado and Diocese of Castello and with suffragan sees Belluno, Chioggia, Cittanova, Feltre and Padova) |
| 1452 | Italy | Diocese of Montepeloso was restored (from Diocese of Andria and without ecclesiastical province) |
| 1452.07.28 | Italy | Diocese of Porto e Santa Rufina was renamed as Diocese of Porto (lost territory to establish Diocese of Santa Rufina) |
| 1452.07.28 | Italy | Diocese of Santa Rufina was restored (from Diocese of Porto e Santa Rufina) |
| 1453 | Romania | Diocese of Milcovia was renamed as Diocese of Milcovia |
| 1454.03.22 | Italy | Diocese of Porto was renamed as Diocese of Porto e Santa Rufina (gained territory from the suppressed Diocese of Santa Rufina) |
| 1454.03.22 | Italy | Diocese of Santa Rufina was suppressed (to Diocese of Porto e Santa Rufina) |
| 1455.04.30 | Italy | Archpresbyterate nullius of Cerignola was established (from Archpresbyterate nullius of Canosa) |
| 1458 | Greece | Metropolitan Archdiocese of Patrasso was suppressed |
| 1459 | Serbia | Archdiocese of Bač was suppressed (to Metropolitan Archdiocese of Kalocsa) |
| 1459.04.23 | Italy | Diocese of Siena was promoted as Metropolitan Archdiocese of Siena (with suffragan sees Chiusi, Grosseto, Massa Marittima e Populonia and Sovana) |
| 1460 |  Croatia | Diocese of Corbavia was suppressed (to establish Diocese of Modruš) |
| 1460 | Croatia | Diocese of Modruš was established (from the suppressed Diocese of Corbavia) |
| 1460 | Croatia | Diocese of Otočac was established (from Diocese of Senj) |
| 1460 | Ireland, Northern Ireland | Diocese of Brefinnia was renamed as Diocese of Kilmore |
| 1460.01.14 |  Germany | Abbacy nullius of Ellwangen was demoted as Provostry nullius of Ellwangen |
| 1461.12.06 |  Slovenia | Diocese of Ljubljana was restored (from Patriarchal See of Aquileia and became suffragan of Aquileia) |
| 1462 |  Palestine | Titular Episcopal See of Bethlehem was restored |
| 1462.08.13 | Italy | Diocese of Montalcino was established (from Diocese of Arezzo, Diocese of Chiusi and Diocese of Grosseto) |
| 1462.08.13 | Italy | Diocese of Pienza was established (from Diocese of Arezzo and Diocese of Chiusi) |
| 1463.09.05 | Italy | Provostry nullius of Santo Stefano di Prato was established (from Diocese of Pistoia and without ecclesiastical province) |
| 1465.07.21 | Italy | Diocese of Luni was renamed as Diocese of Luni–Sarzana |
| 1466 | Italy | Diocese of Equilio was suppressed (to Patriarchal See of Venezia) |
| 1469.01.18 |  Austria | Diocese of Wien was established (from Diocese of Passau and became suffragan of Salzburg) |
| 1469.01.18 | Austria | Diocese of Wiener Neustadt was established (from Metropolitan Archdiocese of Salzburg and became suffragan of Salzburg) |
| 1470 |  Albania | Diocese of Konavlje was suppressed |
| 1471 | Italy | Archpresbyterate nullius of Guastalla was established (from Diocese of Reggio Emilia) |
| 1471 |  Russia | Diocese of Tana was suppressed |
| 1472.08.17 |  Scotland | Diocese of Saint Andrews was promoted as Metropolitan Archdiocese of Saint Andrews (with suffragan sees Aberdeen, Brechin, Caithness, Dunblane, Dunkeld, Kirkwall, Moray and Ross) |
| 1472.08.21 | Morocco | Diocese of Marruecos was established (from Diocese of Ceuta and became suffragan of Lisboa) |
| 1474 |  Czechia | Diocese of Litomyšl was suppressed (to Metropolitan Archdiocese of Praha) |
| 1474.04.18 | Italy | Diocese of Casale Monferrato was established (from Diocese of Asti and Diocese of Vercelli and became suffragan of Milano) |
| 1475 | Ukraine | Diocese of Caffa was suppressed |
| 1475.12.21 | France | Diocese of Avignon was promoted as Metropolitan Archdiocese of Avignon (with suffragan sees Carpentras, Cavaillon and Vaison) |
| 1480 | Italy | Collegiate nullius of Montepulciano was established (from Diocese of Arezzo) |
| 1483 | Greece | Metropolitan Archdiocese of Athens was suppressed |
| 1484.08.28 | Ireland | Collegiate nullius of Saint Nicholas was established (from Diocese of Annaghdown) |
| 1485 | Spain | Diocese of Islas Canarias was established (from the suppressed Diocese of Rubicón and became suffragan of Sevilla) |
| 1485 | Spain | Diocese of Rubicón was suppressed (to establish Diocese of Islas Canarias) |
| 1485 | Ukraine | Diocese of Cembalo was suppressed |
| 1486.08.04 | Spain | Diocese of Málaga was restored |
| 1492.01.09 | Scotland | Diocese of Glasgow was promoted as Metropolitan Archdiocese of Glasgow (with suffragan sees Argyll, Kirkwall and Whithorn) |
| 1492.05.21 | Spain | Diocese of Almería was established (from Diocese of Cartagena and former Diocese of Urci) |
| 1492.05.21 | Spain | Titular Episcopal See of Baza was suppressed (to establish Diocese of Guadix–Baza) |
| 1492.05.21 | Spain | Diocese of Guadix–Baza was restored (from Diocese of Cartagena, from the suppressed Titular Episcopal See of Baza and became suffragan of Toledo) |
| 1492.07.09 | Spain | Diocese of Valencia was promoted as Metropolitan Archdiocese of Valencia (with suffragan sees Cartagena, Mallorca and Segorbe–Albarracín) |
| 1492.12.10 | Spain | Metropolitan Archdiocese of Granada was restored (with suffragan sees Almería, Guadix–Baza, Jaén and Málaga) |
| 1495.06.21 | Italy | Diocese of Sabina was established (from Diocese of Vescovìo and became suffragan of Roma) |
| 1495.09.11 | Italy | Diocese of Galtellì was suppressed (to Metropolitan Archdiocese of Cagliari) |
| 1495.09.18 | Italy | Diocese of Vescovìo was suppressed (to Diocese of Sabina) |
| 1496 | Morocco | Titular Episcopal See of Fez was restored |
| 1500 | Albania | Diocese of Balecio was suppressed |
| 1500 | Albania | Diocese of Craina was suppressed |
| 1500 | Algeria | Titular Episcopal See of Calama was restored |
| 1500 |  Cyprus | Titular Episcopal See of Ceraunia was established |
| 1500 | Greece | Metropolitan Archdiocese of Corinthus was suppressed |
| 1500 | Greece | Diocese of Coronea was suppressed |
| 1500 | Greece | Diocese of Karpathus was suppressed |
| 1500 | Greece | Metropolitan Archdiocese of Mytilene was suppressed |
| 1500 | Greece | Archdiocese of Patrae Veteres was suppressed |
| 1500 | Greece | Diocese of Sitia was established |
| 1500 | Lebanon | Archdiocese of Beirut (Maronite Rite) was established (without ecclesiastical province) |
| 1500 | Palestine | Titular Episcopal See of Maioren was established |
| 1500 | Serbia | Titular Episcopal See of Beograd was established (from Diocese of Beograd) |
| 1500 |  Syria | Titular Episcopal See of Arethusus was restored |
| 1500 |  Tunisia | Titular Episcopal See of Utica was restored |
| 1500 |  Turkiye | Titular Archiepiscopal See of Colossæ was restored |
| 1500 | Turkiye | Diocese of Focea was suppressed |
| 1500 | Turkiye | Titular Metropolitan See of Laodicea was restored |
| 1500 | Turkiye | Titular Archiepiscopal See of Nazianzus was restored |
| 1500 | Turkiye | Titular Episcopal See of Parium was restored |
| 1500 | Ukraine | Diocese of Soldaia was suppressed |
