Mr Ellis, who oversees speech and music production teams across the BBC's radio stations, is to advise the Vatican on it's NEWS.VA website, Vatican Radio outlet, among other services.
He's among 13 new appointments - six priests, six laymen and one laywoman - assisting the Vatican Secretariat for Communications body.
Mr Ellis also serves as president of the Euroradio committee with the European Broadcasting Union - the union is a collection of public service broadcasters from 56 countries.
Jesuit Fr James Martin, the editor-at-large of the Jesuit magazine America, and Michael Warsaw, Chief Executive Office of the EWTN Global Catholic Network broadcaster, are also joining the body.
As new consultors or advisors, their roles are seperate from the secretariat members themselves.
Other new additions include Ann Carter, co-founder of Rasky Baerlein Strategic Communications; Michael Unland, executive director of the Catholic Media Council; and Dino Cataldo Dell'Accio, an ICT expert.