Emiliano Martinez becomes Aston Villa third major signing of the summer, following the arrivals of Ollie Watkins and Matty Cash.
The goalkeeper put pen to paper on a four year deal from Arsenal for a fee of £16m which could rise to £20m with add-ons.
The 28 year old still had two years left on his Arsenal’s contract and impressed when stepping in for number one Bernd Leno following the German’s injury.
The Argentina International kept nine clean sheets in 23 appearances and helped the Gunners win the FA Cup and the Community Shield.
Aston Villa coach Dean Smith said of the signing, “We are really pleased with the signing of our new goalkeeper Emiliano Martinez.
“We know how highly Arsenal rated him and we watched his outstanding performances last season in a trophy winning top side.”