| Date | Age | Event | Bishop | Title | Current Title |
| 1 May | 43.3 | Ordained Bishop | Matthew Man-oso Ndagoso | Bishop of Maiduguri, Nigeria | Archbishop of Kaduna, Nigeria |
| 3 May | 76.2 | Retired | Athanase Bala, C.S.Sp. | Bishop of Bafia, Cameroon | Bishop Emeritus |
| 44.0 | Appointed | Jean-Marie Benoît Balla | Bishop of Bafia, Cameroon |
| 57.9 | Appointed | Stephen Victor Chmilar | Bishop of Toronto (Ukrainian), Canada |
| 93.1 | Died | Jozef Feranec † | Bishop Emeritus of Banská Bystrica, Slovakia |
| 58.1 | Appointed | Diarmuid Martin | Coadjutor Archbishop of Dublin, Ireland | Archbishop |
| 59.7 | Installed | Carlos Germán Mesa Ruiz | Bishop of Arauca, Colombia |
| 76.1 | Retired | Cornelius John Pasichny, O.S.B.M. | Bishop of Toronto (Ukrainian), Canada | Bishop Emeritus |
| 4 May | 45.4 | Ordained Bishop | Antonio Carlos Félix | Bishop of Luz, Minas Gerais, Brazil |
| 38.4 | Ordained Bishop | Wojciech Polak | Titular Bishop of Mons in Numidia | Auxiliary Bishop of Gniezno, Poland |
| 5 May | 57.2 | Appointed | Jean-Yves Riocreux | Bishop of Pontoise, France |
| 6 May | 50.1 | Appointed | Vincent Coulibaly | Archbishop of Conakry {Konakry}, Guinea |
| 78.7 | Died | Francis Paul McHugh, S.F.M. † | Prelate Emeritus of Itacoatiara, Amazonas, Brazil |
| 7 May | 63.9 | Appointed | Antonio Arregui Yarza | Archbishop of Guayaquil, Ecuador |
| 75.7 | Retired | Juan Ignacio Larrea Holguín † | Archbishop of Guayaquil, Ecuador | Archbishop Emeritus |
| 8 May | 78.6 | Died | Carlo Aliprandi † | Bishop Emeritus of Cuneo, Italy |
| 9 May | 97.4 | Died | Louis Henri Marie Ferrand † | Archbishop Emeritus of Tours, France |
| 10 May | 52.1 | Ordained Bishop | Abraham Desta | Titular Bishop of Horrea Aninici | Vicar Apostolic of Meki, Ethiopia |
| 62.8 | Installed | Guillermo José Garlatti | Archbishop of Bahía Blanca, Argentina |
| 79.1 | Died | Adolfo Rodríguez Herrera † | Archbishop Emeritus of Camagüey, Cuba |
| 11 May | 49.5 | Ordained Bishop | Jean-Luc Marie Maurice Louis Bouilleret | Bishop of Amiens, France |
| 56.1 | Ordained Bishop | Alfred Maria Oburu Asue, C.M.F. † | Bishop of Ebebiyin, Equatorial Guinea |
| 12 May | 74.5 | Retired | Juan Martí Alanis | Bishop of Urgell, Spain | Bishop Emeritus |
| 53.8 | Succeeded | Joan Enric Vives Sicilia | Bishop of Urgell, Spain |
| 13 May | 43.5 | Appointed | Volodymyr Viytyshyn | Coadjutor Bishop of Kolomyia-Chernivtsi (Ukrainian), Ukraine | Bishop of Ivano-Frankivsk [Stanislaviv] (Ukrainian), Ukraine |
| 14 May | 61.5 | Appointed | Daniel Joseph Bohan | Auxiliary Bishop of Toronto, Ontario, Canada | Archbishop of Regina, Saskatchewan, Canada |
| 61.5 | Appointed | Daniel Joseph Bohan | Titular Bishop of Migirpa | Archbishop of Regina, Saskatchewan, Canada |
| 51.3 | Appointed | Luis Albeiro Cortés Rendón | Bishop of Vélez, Colombia |
| 53.9 | Installed | Michael Richard Cote | Bishop of Norwich, Connecticut, USA |
| 70.6 | Appointed | Denis Croteau, O.M.I. | Apostolic Administrator of Whitehorse, Yukon, Canada | Bishop Emeritus of Mackenzie-Fort Smith, Northwest Territory, Canada |
| 51.7 | Ordained Bishop | Mathias Lee Yong-Hoon | Titular Bishop of Catabum Castra | Auxiliary Bishop of Suwon, Korea (South) |
| 56.1 | Ordained Bishop | Pawel Stobrawa | Titular Bishop of Aeca | Auxiliary Bishop of Opole, Poland |
| 60.4 | Appointed | Décio Zandonade, S.D.B. | Bishop of Colatina, Espirito Santo, Brazil |
| 15 May | 63.1 | Ordained Bishop | Paul Tan Chee Ing, S.J. | Bishop of Melaka-Johor, Malaysia |
| 17 May | 69.1 | Appointed | Iwannis Louis Awad | Vicar Apostolic of Venezuela, Faithful of the Oriental Rite (Syrian) |
| 69.1 | Appointed | Iwannis Louis Awad | Titular Bishop of Zeugma in Syria | Vicar Apostolic of Venezuela, Faithful of the Oriental Rite (Syrian) |
| 72.3 | Appointed | Henry Theophilus Howaniec, O.F.M. | Bishop of Santissima Trinitŕ in Almaty, Kazakhstan |
| 53.1 | Appointed | Jan Pawel Lenga, M.I.C. | Archbishop (Personal Title) of Karaganda, Kazakhstan | Bishop |
| 51.7 | Appointed | Tomasz Peta | Archbishop of Maria Santissima in Astana, Kazakhstan |
| 40.0 | Ordained Bishop | Oscar Domingo Sarlinga | Titular Bishop of Uzalis | Bishop of Zárate-Campana, Argentina |
| 18 May | 51.8 | Ordained Bishop | Francesco Beschi | Titular Bishop of Vinda | Auxiliary Bishop of Brescia, Italy |
| 45.5 | Installed | Antonio Carlos Félix | Bishop of Luz, Minas Gerais, Brazil |
| 161.3 | Canonized | St. Józef Sebastian Pelczar † | Bishop of Przemyśl, Poland |
| 62.7 | Ordained Bishop | Yannis Spiteris, O.F.M. Cap. | Archbishop of Corfů, Zante e Cefalonia, Greece |
| 71.6 | Died | Teodoro Ubeda Gramage † | Bishop of Mallorca, Spain |
| 19 May | 49.5 | Ordained Bishop | Christopher Charles Prowse | Titular Bishop of Bahanna | Auxiliary Bishop of Melbourne, Australia |
| 20 May | 73.0 | Died | Michael Praphon Chaicharoen, S.D.B. † | Bishop of Surat Thani, Thailand |
| 21 May | 66.3 | Died | Pierre Nguyęn Van Nho † | Coadjutor Bishop of Nha Trang, Vięt Nam |
| 22 May | 82.3 | Died | Packiam Arokiaswamy † | Bishop Emeritus of Tanjore, India |
| 59.9 | Appointed | Claude-Joseph Azéma | Auxiliary Bishop of Montpellier (, Lodčve, Béziers, Agde, e Saint-Pons-de-Thomičres), France |
| 59.9 | Appointed | Claude-Joseph Azéma | Titular Bishop of Murcona | Auxiliary Bishop of Montpellier (, Lodčve, Béziers, Agde, e Saint-Pons-de-Thomičres), France |
| 55.1 | Appointed | Guy Harpigny | Bishop of Tournai {Doornik}, Belgium |
| 23 May | 47.0 | Installed | Philip Arnold Subira Anyolo | Bishop of Homa Bay, Kenya |
| 76.1 | Retired | William Henry Bullock | Bishop of Madison, Wisconsin, USA | Bishop Emeritus |
| 56.4 | Appointed | Robert Charles Morlino | Bishop of Madison, Wisconsin, USA |
| 24 May | 54.6 | Appointed | Charles Maung Bo, S.D.B. | Archbishop of Yangon, Myanmar |
| 71.1 | Resigned | Anthony Soter Fernandez | Archbishop of Kuala Lumpur, Malaysia | Archbishop Emeritus |
| 49.4 | Appointed | John Hsane Hgyi | Bishop of Pathein, Myanmar |
| 60.5 | Ordained Bishop | Emmanuel Okombo | Bishop of Kericho, Kenya |
| 64.5 | Appointed | Murphy Nicholas Xavier Pakiam | Archbishop of Kuala Lumpur, Malaysia |
| 59.5 | Resigned | Sotero Phamo (Thein Myint) | Apostolic Administrator of Yangon, Myanmar | Bishop of Loikaw, Myanmar |
| 48.4 | Appointed | Ricardo Valenzuela Rios | Bishop of Paraguay, Military |
| 65.2 | Appointed | Paul Zingtung Grawng | Archbishop of Mandalay, Myanmar |
| 25 May | 43.9 | Ordained Bishop | Thierry Marie Jacques Brac de la Perričre | Titular Bishop of Zallata | Auxiliary Bishop of Lyon, France |
| 46.2 | Ordained Bishop | Hervé Jean Robert Giraud | Titular Bishop of Silli | Bishop of Soissons (, Laon, e Saint-Quentin), France |
| 86.2 | Died | George Edward Lynch † | Auxiliary Bishop Emeritus of Raleigh, North Carolina, USA |
| 26 May | 84.8 | Died | Edwin Roy Kinch, O.S.M. † | Prefect Emeritus of Ingwavuma, South Africa |
| 27 May | 60.0 | Appointed | Miklós Beer | Bishop of Vác, Hungary |
| 55.3 | Ordained Bishop | Thomas Anthony Williams | Titular Bishop of Mageó | Auxiliary Bishop of Liverpool, England, Great Britain |
| 29 May | 64.5 | Installed | Murphy Nicholas Xavier Pakiam | Archbishop of Kuala Lumpur, Malaysia |
| 65.8 | Ordained Bishop | Paul Henry Walsh | Titular Bishop of Abthugni | Auxiliary Bishop of Rockville Centre, New York, USA |
| 30 May | 60.0 | Appointed | Guillermo Rodríguez Melgarejo | Bishop of San Martín, Argentina |
| 31 May | 59.9 | Appointed | Benvenuto Italo Castellani | Coadjutor Archbishop of Lucca, Italy | Archbishop |
| 78.4 | Died | Francesco Colasuonno † | Cardinal, Apostolic Nuncio Emeritus to Italy |
| 55.5 | Resigned | José Luis Fletes Santana | Auxiliary Bishop of México, Federal District | Auxiliary Bishop Emeritus |
| 55.3 | Ordained Bishop | Ladislav Hucko | Titular Bishop of Horaea | Bishop of Czech Republic, Faithful of Eastern Rite (Byzantine) |
| 61.2 | Ordained Bishop | Antonio Marino | Titular Bishop of Basti | Auxiliary Bishop of La Plata, Argentina |
| 45.0 | Ordained Bishop | Guillermo Patricio Vera Soto | Prelate of Calama, Chile |