The former Liverpool captain, 41, leaves the Scottish champions having guided them to a first league title in 10 years last season. Gerrard replaces Dean Smith, who was sacked on Sunday after a run of five successive defeats. Villa is 16th in the Premier League, two points above the relegation zone.
“Aston Villa is a club with a rich history and tradition in English football and I am immensely proud to become its new head coach,” said Gerrard.
“In my conversations with [co-owners] Nassef [Sawiris], Wes [Edens] and the rest of the board, it was apparent how ambitious their plans are for the club and I am looking forward to helping them achieve their aims.”
Gerrard took his first steps in senior management with Scottish Premiership side Rangers in 2018 and leaves with them four points clear of rivals Celtic at the top of the table.BBC Sport Scotland understands Villa has paid Rangers £4.5m in compensation.
“Steven and his backroom staff have ensured that the club is undoubtedly in a better place today than it was three-and-a-half years ago,” said Rangers sporting director Ross Wilson.
“We have shared a desire to move Rangers forward, to modernize our infrastructure, and to make the club win again.
“There have been so many areas that we have moved forward, and there is still so much to be done, but I can’t stress enough how important it has been to have with us a first-team manager who shared a drive and desire to set standards and move the whole football operation forward.”