Date | Country | Change |
| 1946 |  Canada | Diocese of Charlottetown lost territory to Diocese of Gaspé |
| 1946 |  Egypt | Titular Episcopal See of Canopus was suppressed |
| 1946 |  Greece | Titular Episcopal See of Thebæ Phthiotides was renamed as Titular Episcopal See of Thebæ Phthiotides |
| 1946 |  Luxembourg | Abbacy nullius of Saint-Maurice et Saint-Maur de Clervaux was suppressed (to Diocese of Luxembourg) |
| 1946 |  Turkiye | Titular Archiepiscopal See of Nacolia was renamed as Titular Archiepiscopal See of Nacolia |
| 1946 | Turkiye | Titular Metropolitan See of Sebastea was renamed as Titular Metropolitan See of Sebastea |
| 1946 | | Titular Episcopal See of Issus was suppressed |
| 1946.01.05 |  Italy | Diocese of Porto e Santa Rufina lost territory to Papal See of Roma |
| 1946.01.11 |  Peru | Apostolic Prefecture of San Francisco Javier was established (from Diocese of Cajamarca, Diocese of Chachapoyas and Apostolic Vicariate of San Gabriel de la Dolorosa del Marañón) |
| 1946.02.09 | Canada | Diocese of Saint-Germain de Rimouski was promoted as Metropolitan Archdiocese of Rimouski (with suffragan sees Gaspé and Golfe Saint-Laurent) |
| 1946.04.11 |  China | Apostolic Vicariate of Anguo 安國 was promoted as Diocese of Anguo 安國 (became suffragan of Beijing 北京) |
| 1946.04.11 | China | Apostolic Vicariate of Anqing 安慶 was promoted as Metropolitan Archdiocese of Anqing 安慶 (with suffragan sees Bengbu 蚌埠 and Wuhu 蕪湖) |
| 1946.04.11 | China | Apostolic Vicariate of Baodingfu 保定府 was promoted as Diocese of Baoding 保定 (became suffragan of Beijing 北京) |
| 1946.04.11 | China | Apostolic Vicariate of Beihai 北海 was promoted as Diocese of Beihai 北海 (became suffragan of Guangzhou 廣州) |
| 1946.04.11 | China | Apostolic Vicariate of Beijing 北京 was promoted as Metropolitan Archdiocese of Beijing 北京 (with suffragan sees Anguo 安國, Baoding 保定, Shunde 順德, Tianjin 天津, Xianxian 獻縣, Xuanhua 宣化, Yongnian 永年, Yongping 永平, Zhaoxian 趙縣 and Zhengding 正定) |
| 1946.04.11 | China | Apostolic Vicariate of Bengbu 蚌埠 was promoted as Diocese of Bengbu 蚌埠 (became suffragan of Anqing 安慶) |
| 1946.04.11 | China | Apostolic Vicariate of Caozhoufu 曹州府 was promoted as Diocese of Caozhou 曹州 (became suffragan of Jinan 濟南) |
| 1946.04.11 | China | Apostolic Vicariate of Changde 常德 was promoted as Diocese of Changde 常德 (became suffragan of Changsha 長沙) |
| 1946.04.11 | China | Apostolic Vicariate of Changsha 長沙 was promoted as Metropolitan Archdiocese of Changsha 長沙 (with suffragan sees Changde 常德, Hengzhou 衡州 and Yuanling 沅陵) |
| 1946.04.11 | China | Apostolic Vicariate of Chengdu 成都 was promoted as Diocese of Chengdu 成都 (became suffragan of Chongqing 重慶) |
| 1946.04.11 | China | Apostolic Vicariate of Chongqing 重慶 was promoted as Metropolitan Archdiocese of Chongqing 重慶 (with suffragan sees Chengdu 成都, Jiading 嘉定, Kangding 康定, Ningyuan 寧遠, Shunqing 順慶, Suifu 敘府 and Wanxian 萬縣) |
| 1946.04.11 | China | Apostolic Vicariate of Datongfu 大同府 was promoted as Diocese of Datong 大同 (became suffragan of Taiyuan 太原) |
| 1946.04.11 | China | Apostolic Vicariate of Fengxiangfu 鳳翔府 was promoted as Diocese of Fengxiang 鳳翔 (became suffragan of Xi’an 西安) |
| 1946.04.11 | China | Apostolic Vicariate of Fenyang 汾陽 was promoted as Diocese of Fenyang 汾陽 (became suffragan of Taiyuan 太原) |
| 1946.04.11 | China | Apostolic Vicariate of Funingfu 福寧府 was promoted as Diocese of Funing 福寧 (became suffragan of Fuzhou 福州) |
| 1946.04.11 | China | Apostolic Vicariate of Fushun 撫順 was promoted as Diocese of Fushun 撫順 (became suffragan of Shenyang 瀋陽) |
| 1946.04.11 | China | Apostolic Vicariate of Fuzhou 福州 was promoted as Metropolitan Archdiocese of Fuzhou 福州 (with suffragan sees Funing 福寧 and Xiamen 廈門) |
| 1946.04.11 | China | Apostolic Vicariate of Ganzhou 贛州 was promoted as Diocese of Ganzhou 贛州 (became suffragan of Nanchang 南昌) |
| 1946.04.11 | China | Apostolic Vicariate of Guangzhou 廣州 was promoted as Metropolitan Archdiocese of Guangzhou 廣州 (with suffragan sees Beihai 北海, Hong Kong 香港, Jiangmen 江門, Jiaying 嘉應, Shantou 汕頭 and Shaoguan 韶關) |
| 1946.04.11 | China | Apostolic Vicariate of Guiyang 貴陽 was promoted as Metropolitan Archdiocese of Guiyang 貴陽 (with suffragan see Nanlong 南龍) |
| 1946.04.11 | China | Apostolic Vicariate of Haimen 海門 was promoted as Diocese of Haimen 海門 (became suffragan of Nanjing 南京) |
| 1946.04.11 | China | Apostolic Vicariate of Hangzhou 杭州 was promoted as Metropolitan Archdiocese of Hangzhou 杭州 (with suffragan sees Linhai 臨海 and Ningbo 寧波) |
| 1946.04.11 | China | Apostolic Vicariate of Hankou 漢口 was promoted as Metropolitan Archdiocese of Hankou 漢口 (with suffragan sees Hanyang 漢陽, Laohekou 老河口, Qichun 蘄春, Shinan 施南, Wuchang 武昌 and Yichang 宜昌) |
| 1946.04.11 | China | Apostolic Vicariate of Hanyang 漢陽 was promoted as Diocese of Hanyang 漢陽 (became suffragan of Hankou 漢口) |
| 1946.04.11 | China | Apostolic Vicariate of Hanzhongfu 漢中府 was promoted as Diocese of Hanzhong 漢中 (became suffragan of Xi’an 西安) |
| 1946.04.11 | China | Apostolic Vicariate of Hengzhou 衡州 was promoted as Diocese of Hengzhou 衡州 (became suffragan of Changsha 長沙) |
| 1946.04.11 | China | Apostolic Vicariate of Jiading 嘉定 was promoted as Diocese of Jiading 嘉定 (became suffragan of Chongqing 重慶) |
| 1946.04.11 | China | Apostolic Vicariate of Jiangmen 江門 was promoted as Diocese of Jiangmen 江門 (became suffragan of Guangzhou 廣州) |
| 1946.04.11 | China | Apostolic Vicariate of Jiaying 嘉應 was promoted as Diocese of Jiaying 嘉應 (became suffragan of Guangzhou 廣州) |
| 1946.04.11 | China | Apostolic Vicariate of Jilin 吉林 was promoted as Diocese of Jilin 吉林 (became suffragan of Shenyang 瀋陽) |
| 1946.04.11 | China | Apostolic Vicariate of Jinanfu 濟南府 was promoted as Metropolitan Archdiocese of Jinan 濟南 (with suffragan sees Caozhou 曹州, Qingdao 青島, Yanggu 陽穀, Yantai 煙臺, Yanzhou 兗州, Yizhou 沂州 and Zhoucun 周村) |
| 1946.04.11 | China | Apostolic Vicariate of Jining 集寧 was promoted as Diocese of Jining 集寧 (became suffragan of Suiyuan 綏遠) |
| 1946.04.11 | China | Apostolic Vicariate of Weihuifu 衛輝府 was promoted as Diocese of Jixian 級縣 (became suffragan of Kaifeng 開封) |
| 1946.04.11 | China | Apostolic Vicariate of Ji’anfu 吉安府 was promoted as Diocese of Ji’an 吉安 (became suffragan of Nanchang 南昌) |
| 1946.04.11 | China | Apostolic Vicariate of Kaifengfu 開封府 was promoted as Metropolitan Archdiocese of Kaifeng 開封 (with suffragan sees Jixian 級縣, Luoyang 洛陽, Nanyang 南陽, Shangqiu 商丘, Xinyang 信陽, Zhengzhou 鄭州 and Zhumadian 駐馬店) |
| 1946.04.11 | China | Apostolic Vicariate of Dajianlu 打箭爐 was promoted as Diocese of Kangding 康定 (became suffragan of Chongqing 重慶) |
| 1946.04.11 | China | Apostolic Vicariate of Yunnanfu 雲南府 was promoted as Metropolitan Archdiocese of Kunming 昆明 (with suffragan see Dali 大理) |
| 1946.04.11 | China | Apostolic Vicariate of Lanchowfu 蘭州府 was promoted as Metropolitan Archdiocese of Lanzhou 蘭州 (with suffragan see Qinzhou 秦州) |
| 1946.04.11 | China | Apostolic Vicariate of Laohekou 老河口 was promoted as Diocese of Laohekou 老河口 (became suffragan of Hankou 漢口) |
| 1946.04.11 | China | Apostolic Vicariate of Taizhou 台州 was promoted as Diocese of Linhai 臨海 (became suffragan of Hangzhou 杭州) |
| 1946.04.11 | China | Apostolic Vicariate of Luoyang 洛陽 was promoted as Diocese of Luoyang 洛陽 (became suffragan of Kaifeng 開封) |
| 1946.04.11 | China | Apostolic Vicariate of Luanfu 潞安府 was promoted as Diocese of Lu’an 潞安 (became suffragan of Taiyuan 太原) |
| 1946.04.11 | China | Apostolic Vicariate of Nanchang 南昌 was promoted as Metropolitan Archdiocese of Nanchang 南昌 (with suffragan sees Ganzhou 贛州, Ji’an 吉安, Nancheng 南城 and Yujiang 餘江) |
| 1946.04.11 | China | Apostolic Vicariate of Nancheng 南城 was promoted as Diocese of Nancheng 南城 (became suffragan of Nanchang 南昌) |
| 1946.04.11 | China | Apostolic Vicariate of Nanjing 南京 was promoted as Metropolitan Archdiocese of Nanjing 南京 (with suffragan sees Haimen 海門, Shanghai 上海 and Xuzhou 徐州) |
| 1946.04.11 | China | Apostolic Vicariate of Nanlong 南龍 was promoted as Diocese of Nanlong 南龍 (became suffragan of Guiyang 貴陽) |
| 1946.04.11 | China | Apostolic Vicariate of Nanning 南寧 was promoted as Metropolitan Archdiocese of Nanning 南寧 (with suffragan see Wuzhou 梧州) |
| 1946.04.11 | China | Apostolic Vicariate of Nanyangfu 南陽府 was promoted as Diocese of Nanyang 南陽 (became suffragan of Kaifeng 開封) |
| 1946.04.11 | China | Apostolic Vicariate of Ningbo 寧波 was promoted as Diocese of Ningbo 寧波 (became suffragan of Hangzhou 杭州) |
| 1946.04.11 | China | Apostolic Vicariate of Ningxia 寧夏 was promoted as Diocese of Ningxia 寧夏 (became suffragan of Suiyuan 綏遠) |
| 1946.04.11 | China | Apostolic Vicariate of Ningyuanfu 寧遠府 was promoted as Diocese of Ningyuan 寧遠 (became suffragan of Chongqing 重慶) |
| 1946.04.11 | China | Apostolic Vicariate of Qichun 蘄春 was promoted as Diocese of Qichun 蘄春 (became suffragan of Hankou 漢口) |
| 1946.04.11 | China | Apostolic Vicariate of Qingdao 青島 was promoted as Diocese of Qingdao 青島 (became suffragan of Jinan 濟南) |
| 1946.04.11 | China | Apostolic Vicariate of Qinzhou 秦州 was promoted as Diocese of Qinzhou 秦州 (became suffragan of Lanzhou 蘭州) |
| 1946.04.11 | China | Apostolic Vicariate of Rehe 熱河 was promoted as Diocese of Rehe 熱河 (became suffragan of Shenyang 瀋陽) |
| 1946.04.11 | China | Apostolic Vicariate of Sanyuan 三原 was promoted as Diocese of Sanyuan 三原 (became suffragan of Xi’an 西安) |
| 1946.04.11 | China | Apostolic Vicariate of Shanghai 上海 was promoted as Diocese of Shanghai 上海 (became suffragan of Nanjing 南京) |
| 1946.04.11 | China | Apostolic Vicariate of Guide 歸德 was promoted as Diocese of Shangqiu 商丘 (became suffragan of Kaifeng 開封) |
| 1946.04.11 | China | Apostolic Vicariate of Shantou 汕頭 was promoted as Diocese of Shantou 汕頭 (became suffragan of Guangzhou 廣州) |
| 1946.04.11 | China | Apostolic Vicariate of Shaozhou 韶州 was promoted as Diocese of Shaoguan 韶關 (became suffragan of Guangzhou 廣州) |
| 1946.04.11 | China | Apostolic Vicariate of Shenyang 瀋陽 was promoted as Metropolitan Archdiocese of Shenyang 瀋陽 (with suffragan sees Fushun 撫順, Jilin 吉林, Rehe 熱河, Siping 四平 and Yanji 延吉) |
| 1946.04.11 | China | Apostolic Vicariate of Shinan 施南 was promoted as Diocese of Shinan 施南 (became suffragan of Hankou 漢口) |
| 1946.04.11 | China | Apostolic Vicariate of Shundefu 順德府 was promoted as Diocese of Shunde 順德 (became suffragan of Beijing 北京) |
| 1946.04.11 | China | Apostolic Vicariate of Shunqingfu 順慶府 was promoted as Diocese of Shunqing 順慶 (became suffragan of Chongqing 重慶) |
| 1946.04.11 | China | Apostolic Vicariate of Shuozhou 朔州 was promoted as Diocese of Shuoxian 朔縣 (became suffragan of Taiyuan 太原) |
| 1946.04.11 | China | Apostolic Vicariate of Sipingjie 四平街 was promoted as Diocese of Siping 四平 (became suffragan of Shenyang 瀋陽) |
| 1946.04.11 | China | Apostolic Vicariate of Suifu 敘府 was promoted as Diocese of Suifu 敘府 (became suffragan of Chongqing 重慶) |
| 1946.04.11 | China | Apostolic Vicariate of Suiyuan 綏遠 was promoted as Metropolitan Archdiocese of Suiyuan 綏遠 (with suffragan sees Jining 集寧, Ningxia 寧夏 and Xiwanzi 西灣子) |
| 1946.04.11 | China | Apostolic Vicariate of Taiyuanfu 太原府 was promoted as Metropolitan Archdiocese of Taiyuan 太原 (with suffragan sees Datong 大同, Fenyang 汾陽, Lu’an 潞安, Shuoxian 朔縣 and Yuci 榆次) |
| 1946.04.11 | China | Apostolic Vicariate of Tianjin 天津 was promoted as Diocese of Tianjin 天津 (became suffragan of Beijing 北京) |
| 1946.04.11 | China | Apostolic Vicariate of Wanxian 萬縣 was promoted as Diocese of Wanxian 萬縣 (became suffragan of Chongqing 重慶) |
| 1946.04.11 | China | Apostolic Vicariate of Wuchang 武昌 was promoted as Diocese of Wuchang 武昌 (became suffragan of Hankou 漢口) |
| 1946.04.11 | China | Apostolic Vicariate of Wuhu 蕪湖 was promoted as Diocese of Wuhu 蕪湖 (became suffragan of Anqing 安慶) |
| 1946.04.11 | China | Apostolic Vicariate of Wuzhou 梧州 was promoted as Diocese of Wuzhou 梧州 (became suffragan of Nanning 南寧) |
| 1946.04.11 | China,  Taiwan | Apostolic Vicariate of Amoy 廈門 was promoted as Diocese of Xiamen 廈門 (became suffragan of Fuzhou 福州) |
| 1946.04.11 | China | Apostolic Vicariate of Xianxian 獻縣 was promoted as Diocese of Xianxian 獻縣 (became suffragan of Beijing 北京) |
| 1946.04.11 | China | Apostolic Vicariate of Xinyangzhou 信陽州 was promoted as Diocese of Xinyang 信陽 (became suffragan of Kaifeng 開封) |
| 1946.04.11 | China | Apostolic Vicariate of Xiwanzi 西灣子 was promoted as Diocese of Xiwanzi 西灣子 (became suffragan of Suiyuan 綏遠) |
| 1946.04.11 | China | Apostolic Vicariate of Xi’anfu 西安府 was promoted as Metropolitan Archdiocese of Xi’an 西安 (with suffragan sees Fengxiang 鳳翔, Hanzhong 漢中, Sanyuan 三原 and Yan’an 延安) |
| 1946.04.11 | China | Apostolic Vicariate of Xuanhuafu 宣化府 was promoted as Diocese of Xuanhua 宣化 (became suffragan of Beijing 北京) |
| 1946.04.11 | China | Apostolic Vicariate of Xuzhou 徐州 was promoted as Diocese of Xuzhou 徐州 (became suffragan of Nanjing 南京) |
| 1946.04.11 | China | Apostolic Vicariate of Yanggu 陽穀 was promoted as Diocese of Yanggu 陽穀 (became suffragan of Jinan 濟南) |
| 1946.04.11 | China | Apostolic Vicariate of Yanji 延吉 was promoted as Diocese of Yanji 延吉 (became suffragan of Shenyang 瀋陽) |
| 1946.04.11 | China | Apostolic Vicariate of Zhifou 芝罘 was promoted as Diocese of Yantai 煙臺 (became suffragan of Jinan 濟南) |
| 1946.04.11 | China | Apostolic Vicariate of Yanzhoufu 兗州府 was promoted as Diocese of Yanzhou 兗州 (became suffragan of Jinan 濟南) |
| 1946.04.11 | China | Apostolic Vicariate of Yan’anfu 延安府 was promoted as Diocese of Yan’an 延安 (became suffragan of Xi’an 西安) |
| 1946.04.11 | China | Apostolic Vicariate of Yichang 宜昌 was promoted as Diocese of Yichang 宜昌 (became suffragan of Hankou 漢口) |
| 1946.04.11 | China | Apostolic Vicariate of Yizhoufu 沂州府 was promoted as Diocese of Yizhou 沂州 (became suffragan of Jinan 濟南) |
| 1946.04.11 | China | Apostolic Vicariate of Yongnian 永年 was promoted as Diocese of Yongnian 永年 (became suffragan of Beijing 北京) |
| 1946.04.11 | China | Apostolic Vicariate of Yongpingfu 永平府 was promoted as Diocese of Yongping 永平 (became suffragan of Beijing 北京) |
| 1946.04.11 | China | Apostolic Vicariate of Yuanling 沅陵 was promoted as Diocese of Yuanling 沅陵 (became suffragan of Changsha 長沙) |
| 1946.04.11 | China | Apostolic Vicariate of Yuci 榆次 was promoted as Diocese of Yuci 榆次 (became suffragan of Taiyuan 太原) |
| 1946.04.11 | China | Apostolic Vicariate of Yujiang 餘江 was promoted as Diocese of Yujiang 餘江 (became suffragan of Nanchang 南昌) |
| 1946.04.11 | China | Apostolic Vicariate of Zhaoxian 趙縣 was promoted as Diocese of Zhaoxian 趙縣 (became suffragan of Beijing 北京) |
| 1946.04.11 | China | Apostolic Vicariate of Zhengdingfu 正定府 was promoted as Diocese of Zhengding 正定 (became suffragan of Beijing 北京) |
| 1946.04.11 | China | Apostolic Vicariate of Zhengzhou 鄭州 was promoted as Diocese of Zhengzhou 鄭州 (became suffragan of Kaifeng 開封) |
| 1946.04.11 | China | Apostolic Vicariate of Zhoucun 周村 was promoted as Diocese of Zhoucun 周村 (became suffragan of Jinan 濟南) |
| 1946.04.11 | China | Apostolic Vicariate of Zhumadian 駐馬店 was promoted as Diocese of Zhumadian 駐馬店 (became suffragan of Kaifeng 開封) |
| 1946.04.11 |  Hong Kong | Apostolic Vicariate of Hong Kong 香港 was promoted as Diocese of Hong Kong 香港 (became suffragan of Guangzhou 廣州) |
| 1946.04.11 |  Tanzania | Apostolic Vicariate of Musoma-Maswa was established (from Apostolic Vicariate of Mwanza) |
| 1946.04.13 |  Brazil | Diocese of Petrópolis was established (from Diocese of Barra do Piraí and Diocese of Niterói and became suffragan of São Sebastião do Rio de Janeiro) |
| 1946.05.10 | Tanzania | Apostolic Vicariate of Tanganyika was renamed as Apostolic Vicariate of Karema (lost territory to establish Apostolic Vicariate of Kigoma) |
| 1946.05.10 | Tanzania | Apostolic Vicariate of Kigoma was established (from Apostolic Vicariate of Tanganyika) |
| 1946.06.13 |  Papua New Guinea | Apostolic Vicariate of Papua was renamed as Apostolic Vicariate of Port Moresby (lost territory to establish Apostolic Prefecture of Samarai) |
| 1946.06.13 | Papua New Guinea | Apostolic Prefecture of Samarai was established (from Apostolic Vicariate of Papua) |
| 1946.06.13 |  Zambia | Apostolic Prefecture of Broken Hill was renamed as Apostolic Prefecture of Lusaka |
| 1946.06.22 | Egypt,  South Sudan,  Sudan | Diocese of Cairo (Maronite Rite) was established (without ecclesiastical province) |
| 1946.07.04 |  Micronesia,  Palau | Apostolic Vicariate of Mariana, Caroline, and Marshall Islands was renamed as Apostolic Vicariate of Caroline and Marshall Islands (lost territory to Apostolic Vicariate of Guam) |
| 1946.07.11 |  India | Apostolic Prefecture of Gorakhpur was established (from Diocese of Allahabad and became suffragan of Agra) |
| 1946.08.10 | Peru | Diocese of Ica was established (from Metropolitan Archdiocese of Lima and became suffragan of Lima) |
| 1946.11.09 |  Chile | Apostolic Administration of Copiapó was established (from Metropolitan Archdiocese of La Serena) |
| 1946.11.14 |  Colombia | Mission sui juris of San Andrés y Providencia was promoted as Apostolic Prefecture of San Andrés y Providencia |
| 1946.11.14 |  Zimbabwe | Apostolic Prefecture of Fort Victoria was established |
