The Roman Catholic Diocese of Carolina () is a suffragan diocese in the ecclesiastical province of São LuÃÂs do Maranhão in northeastern Brazil's Maranhão state.
Its cathedral episcopal see is Catedral São Pedro de Alcântara, dedicated to Saint Peter of Alcantara, in the city of Carolina, Maranhão.
As per 2015, it pastorally served 158,100 Catholics (89.9% of 175,800 total) on 18,252 kmò in 11 parishes and 1 mission with 12 priests (diocesan), 2 lay religious (2 sisters) and 4 seminarians.
(all Roman Rite)