The Roman Catholic Diocese of Charlottetown is a diocese of the Catholic Church in Canada. It is a suffragan diocese comprising the entire province of Prince Edward Island.

The Catholic Church in Canada, is part of the worldwide Catholic Church, and has a decentralised structure, meaning each diocesan bishop is autonomous but under the spiritual leadership of the Pope and the Canadian Conference of Catholic Bishops. As of 2021, it has the largest number of adherents to a Christian denomination and a religion in Canada, with 29.4% of Canadians being adherents according to the census in 2021. There are 73 dioceses and about 7,000 priests in Canada. On a normal Sunday, between 15 and 25 percent of Canada's Catholics attend Mass.