Birighitti will travel to Italy on Tuesday to finalise the move and will be with AS Varese until the end of June 2015.
The agreement includes an option for the Italian club to purchase the player after the initial loan period.
It follows the 23-year-old's unsuccessful trial with Bundesliga club Bayer Leverkusen in March last year.
The Perth native joined Newcastle Jets in January 2012 from Adelaide United.
The rising shot-stopper was first choice goalkeeper at the Hunter outfit until recently when he was supplanted by Newcastle local and long-time club stalwart Ben Kennedy.
He is the latest player to exit the club which has endured a horror run this season and currently sits one from the bottom of the A-League ladder.
On Saturday, Phil Stubbins' men were humiliated 7-0 by Adelaide United at Coopers Stadium.
Birighitti has one Socceroos cap to his name and was part of Ange Postecoglou's extended squad for the World Cup in Brazil.