The July 22-29 trip for the Argentine pope, a champion of the poor and disenfranchised, will also include a visit to Rio's Manguinhos slum and a meeting with young inmates.
Pope Francis' charisma and the fact that he is Argentinian are expected to prompt a surge in attendance at the six-day World Youth Day, an event that has been held every two or three years since 1985.
The 76-year-old pontiff, elected in March, will visit the National Shrine of Our Lady of Aparecida, considered a patron of Brazil, the world's most populous Catholic country, on July 24.
Aparecida is some 240 kilometres (150 miles) southwest of Rio.
The pope has no events scheduled for July 23, his first full day in Brazil, designated for rest after the long journey from Rome.
On July 25, he will address a crowd of young people on Rio's Copacabana beach and bless the flags of the 2016 Olympics to be held in Brazil. He visits the Manguinhos slum the same day.
The Vatican said he will then on July 26 meet young inmates and take confessions from some of the participants in World Youth Day and preside over a procession in Copacabana.
On July 27, the pope will meet with Brazilian political and religious leaders and hold a mass prayer vigil in Campus Fidei de Guaratiba on the outskirts of Rio.
Francis will round off the trip with an outdoor mass on Sunday, July 28, and return to Rome the following day.