"Youthfest"), is an annual festival of Catholic youth organized in Medjugorje, Bosnia and Herzegovina, between 1 and 6 August, to mark the birthday of Virgin Mary, mother of Jesus on 5 August, as claimed by the alleged seers of the presumed local Marian apparitions.

The festival was established in 1989 by two Franciscan priests, Slavko Barbarić and Tomislav Vlašić.

Mladifest was established in 1989 by the two Herzegovinian Franciscans – Slavko Barbarić and Tomislav Vlašić – in order to celebrate Virgin Mary's alleged 2000th birthday, as claimed by the alleged seers of Our Lady of Medjugorje.

At the time, Barbarić was sentenced for disobedience to the Church and was illegally active in Medjugorje until 2000.

[4] At the 2020 gathering, Pope Francis sent a message to the attendees stating that the Virgin Mary is "the great model of a Church with a young heart, ready to follow Christ with freshness and docility" and that her example should "always fascinate us and guide us".