High school and then the University of Padua where he graduated in History of the Greek Language. 

He worked at the Padua office of the newspaper Il Gazzettino and from 1992 to 1996 he was editor and Vatican expert of the international magazine 30Giorni, based in Rome. 

From 1996 to 2011 he worked for the newspaper Il Giornale, first as editor and then, since 2001, as a special envoy and Vatican expert, following the travels of John Paul II and Benedict XVI, and the activity of the Holy See. 

In April 2011 he moved to La Stampa, where’s Vatican expert, senior editor and coordinator of the web channel in five languages «Vatican Insider» that the Turin newspaper has put online by June 2011 to 2018: a team working there Vatican experts of international and has become a reference point for the Vatican and religious information, with more than half of the accesses from abroad articles and newspapers in Arabic and Chinese languages. 

He is the author of over fifty books on the history of the Church and on the historicity of the Gospels, many of whom also translated abroad. 

He has already devoted three books to Pope Francis: a biography (Francesco. Insieme, Piemme 2013), a collection of anecdotes (I Fioretti di Papa Francesco, Piemme 2013) and Papa Francesco. Questa economia uccide (Piemme 2015). In January 2016 it was published his book-length interview with Pope Bergoglio (Il nome di Dio è misericordia), a conversation dedicated to the main theme of the extraordinary Jubilee. The book was released simultaneously in 89 countries around the world, translated into 26 languages. 

From 2007 Tornielli is the owner of the blog: «Sacri palazzi». 

Since December 2018 he has the editorial direction of all the Vatican media platforms 

He lives in Milan and Rome. He is married and father of three children.