Lord Patten oversaw Pope Benedict's visit to the UK in 2010 before becoming Chairman of the governing body of the BBC a year later.
He stood down from that role in May this year and will now advise Pope Francis on how to modernise the Vatican's media strategy.
The Vatican said Lord Patten, who's a practising Roman Catholic, will be tasked with making "substantial financial savings".
It's thought he'll spend most of his time building a strategy to bring the churches message to a younger audience.
The pontiff already has a website and nine Twitter accounts in a range of languages.
There are six different communications departments at the Vatican including press, internet and a radio station which broadcasts in 40 languages.