The new Manchester United boss is apparently going to donate his fee from the movie 'Fe' (which means faith in English) to a charity helping poorer children.
It's understood the Portuguese father-of-two will voice the pontiff in English, Portuguese, Spanish and Italian for the film about an apparition of the Virgin Mary in central Portugal.
The movie is expected to be released in May 2017, the 100th anniversary of the apparitions of the Virgin Mary to three children in the village of Fátima.
Gestifute, the Portuguese firm of Mourinho's well-known agent Jorge Mendes, told Premier it was unable to confirm the reports.
The production company behind Fe, Imaginew, has been quoted by the Daily Record newspaper in Scotland as saying Mourinho accepted the role "without reticence or demands."
The Shrine of Our Lady of Fátima is thought to be visited by approximately four million people each year and one of "the most famous Marion shrines in the world."