The two men discussed world affairs and religion, in what the Vatican called an "informal and friendly" encounter.
Before the meeting, Pope Francis gave a homily in which he urged Cubans to serve each other rather than ideology.
It is the first visit by the Pope to the Communist-ruled island, on a trip that will later take him to the US.
Vatican spokesman Father Federico Lombardi described the meeting between Pope Francis and Fidel Castro, which took place at the former Cuban leader's home, as low-key.
They exchanged books: Pope Francis gave Mr Castro three titles, including a book of sermons by Mr Castro's former teacher, while in return the Pope received Fidel and Religion, a collection of interviews with a Brazilian priest.
Before the meeting, Pope Francis gave a homily in which he urged Cubans to serve each other rather than ideology.
It is the first visit by the Pope to the Communist-ruled island, on a trip that will later take him to the US.
Vatican spokesman Father Federico Lombardi described the meeting between Pope Francis and Fidel Castro, which took place at the former Cuban leader's home, as low-key.
They exchanged books: Pope Francis gave Mr Castro three titles, including a book of sermons by Mr Castro's former teacher, while in return the Pope received Fidel and Religion, a collection of interviews with a Brazilian priest.
