The 1991 World Youth Day (Polish: Światowe Dni Młodzieży 1991) was held on 10–15 August 1991 in Jasna Góra in Częstochowa, Poland.

The choice of another European city after Santiago de Compostela meant that, so far unique, two consecutive world days were held in the "old continent".

In the Message for the World Youth Day, announced on 15 August 1990 in the Vatican, John Paul II reminded the role of the Holy Spirit in Christian life.

The theme chosen by Pope John Paul II from these days is the eighth chapter of the Epistle to the Romans, verse 15: "You have received a spirit of children."

[6] Pope John Paul II used Esperanto to address young people present at Mount Hela at the opening and closing of WYD.