The 23-year-old moves to Villa Park after signing a new contract with the Red Devils until the summer of 2023.
Tuanzebe has previously enjoyed two loan spells at Aston Villa. He made five appearances in his first spell in the second half of the 2017/2018 season.
His second loan spell at the club came the following season, where he made 28 championship appearances to help Aston Villa earn promotion back to the Premier League.
Tuanzebe made 19 appearances across all competitions for Manchester United last season but is expected to fall further down the pecking order with the expected arrival of French world cup winning defender Raphael Varane from Real Madrid.
Tuanzebe is Aston Villa’s fifth summer signing following the arrivals of Ashley Young, Emiliano Buendia, Leon Bailey and Danny Ings.
Dean Smith’s side have however lost the services of club captain Jack Grealish, who joined champions Manchester City in a £100m move last week.
Tuanzebe will fight it out with the likes of Tyrone Mings, Ezri Konsa and Kortney Hause for a starting berth in central defence for Aston Villa.
Aston Villa will start their 2021/2022 campaign away at newly-promoted Watford on August 14.
