| Jurisdiction: | Diocese |
| Sendai | |
| Local: | Japanese: カトリック仙台教区 |
| Latin: | Dioecesis Sendaiensis |
| Country: | Japan |
| Territory: | Miyagi, Aomori, Fukushima, and Iwate |
| Metropolitan: | Tokyo |
| Province: | Tokyo |
| Rite: | Latin Rite |
| Cathedral: | Cathedral of Saints Peter and Paul, Sendai |
| Area Km2: | 45,951 |
| Population: | 7,167,150 |
| Population As Of: | 2010 |
| Catholics: | 10,949 |
| Catholics Percent: | 0.2 |
| Metro Archbishop: | Tarcisio Isao Kikuchi |
| Emeritus Bishops: | Martin Tetsuo Hiraga |
| Map: | Giappone - Diocesi di Sendai.png |
| Website: | http://www.sendai.catholic.jp/ |
The Diocese of Sendai (Latin: Dioecesis Sendaiensis, Japanese: カトリック仙台教区) is a Latin Church diocese of the Catholic Church centered in the city of Sendai. It is within the ecclesiastical province of Archdiocese of Tokyo in Japan.
On April 17, 1891, the Roman Catholic Diocese of Hakodate was carved out of the Apostolic Vicariate of Northern Japan. On March 9, 1936 the diocese was renamed the Diocese of Sendai.