The Catholic Church, also known as the Roman Catholic Church, is the world's largest Christian church, with over a billion members. Led by the Pope, it defines its mission as spreading the gospel of Jesus Christ, administering its sacraments and exercising charity. The Roman Catholic Church is among the oldest institutions in the world and has played a prominent role in the history of Western civilisation. It teaches that it is the one true church founded by Jesus Christ, that its bishops are the successors of Christ's apostles and that the Pope is the sole successor to Saint Peter.

Roman Catholic doctrine maintains that the Church is infallible when it definitively teaches a doctrine of faith or morals. Catholic worship is centred on the Eucharist, in which the Church teaches that the sacramental bread and wine are transubstantiated into the body and blood of Christ. The Church holds the Blessed Virgin Mary in special regard. Catholic beliefs concerning Mary include her Immaculate Conception and bodily Assumption at the end of her earthly life.