Smith guided Villa back to the Premier League last season via the Championship play-offs after replacing Steve Bruce at Villa Park in October 2018.
“I’m really happy to have committed my long-term future to the club,” said Smith. “I’m looking forward to all the challenges that come with re-establishing Aston Villa as a top Premier League club.”
Chief executive Christian Purslow said: “The board is delighted that Dean has signed a new four-year contract which puts him at the heart of the club’s long-term rebuilding plans.”
Villa are 15th in the Premier League table following Monday’s 2-0 win over Newcastle.
