| Jurisdiction: | Diocese |
| Tsiroanomandidy | |
| Latin: | Dioecesis Tsiroanomandidyensis |
| Country: | Madagascar |
| Metropolitan: | Antananarivo |
| Rite: | Latin Rite |
| Area Km2: | 40,000 |
| Population: | 464,211 |
| Population As Of: | 2004 |
| Catholics: | 172,189 |
| Catholics Percent: | 37.1 |
| Bishop: | Gabriel Randrianantenaina |
The Roman Catholic Diocese of Tsiroanomandidy (Latin: Tsiroanomandidyen(sis)) is a suffragan Latin diocese in the ecclesiastical province of Antananarivo in Madagascar, yet depends on the missionary Roman Congregation for the Evangelization of Peoples.
Its cathedral episcopal see is the (Marian) Cathédrale Notre Dame du Bon Remède, in Tsiroanomandidy, Antananarivo Province.
As per 2014, it pastorally served 223,433 Catholics (37.2% of 600,167 total) on 40,000 km2 in 3 parishes and 19 missions with 45 priests (28 diocesan, 17 religious), 168 lay religious (36 brothers, 132 sisters) and 32 seminarians.
(all Roman rite; so far -mostly European missionary- members of Latin congregations)