The 31-year-old international player from Argentina has decided to stay through 2029.
Martinez spent £17 million to join Villa from Arsenal in 2020, and he has since made over 150 appearances for the team.
In 34 Premier League games last season, the 2022 World Cup winner maintained nine clean sheets, helping Unai Emery’s team finish fourth and earn a first-ever Champions League qualification.
He participated in all six matches this summer as Argentina won the Copa America a record 16 times.
