Viviano joins the Gunners from Serie B side Palermo having spent last season on loan at Fiorentina.
The 27-year-old is expected to provide competition for places with the likes of Wojciech Szczesny and Lukasz Fabianksi, and Wenger believes that his experience at the highest level will help the Gunners.
"Viviano is a player that we have rated for some time and we are very pleased to have signed him on loan," Wenger told the club's official website.
"He's experienced and has proved himself at a high level, and provides us with excellent cover to our existing goalkeepers."
Viviano, who has won six caps for Italy, is Arsenal's first signing on deadline day, although he is expected to be joined by Real Madrid's Mesut Ozil before the window shuts.