| Jurisdiction: | Diocese |
| Kaišiadorys | |
| Latin: | Dioecesis Kaisiadorensis |
| Local: | Vyskupija Kaišiadorių |
| Country: |  Lithuania |
| Metropolitan: | Vilnius |
| Rite: | Latin Rite |
| Sui Iuris Church: | Latin Church |
| Cathedral: | Transfiguration Cathedral |
| Area Km2: | 6,557 |
| Population: | 118,000 |
| Population As Of: | 2016 |
| Catholics: | 100,000 |
| Catholics Percent: | 84.7 |
| Metro Archbishop: | Gintaras Grušas |
| Emeritus Bishops: | Juozapas Matulaitis-Labukas |
| Map: | Lituania - Diocesi di Kaišiadorys.png |
| Website: | Website of the Diocese |
| Patron: | St Joseph |
The Roman Catholic Diocese of Kaišiadorys (Latin: Kaisiadorensis) is a diocese located in the city of Kaišiadorys in the Ecclesiastical Province of Vilnius in Lithuania. It was established on 4 April 1926 from the Metropolitan Archdiocese of Vilnius.
(all Roman Rite)
Between 1982 and 1991, Kaišiadorys was led by Apostolic Administrators rather than bishops.