By SABC Sport
29th June 2024
The 22-year-old left-back was part of the Borussia Dortmund team beaten by Real Madrid in last season's Champions League final during a loan move from Stamford Bridge.
Maatsen, who is currently with his country at Euro 2024 in Germany, becomes Unai Emery's second summer signing following the arrival of forward Lewis Dobbin from Everton.
Villa are preparing for Champions League football after finishing fourth in the top flight.
Maatsen registered 16 appearances in the Bundesliga and seven in the Champions League for Dortmund, including scoring in the German club's European quarter-final triumph over Atletico Madrid.
He also played 12 Premier League games for Chelsea last term, having previously been loaned to Charlton, Coventry and Burnley.
Meanwhile, Chelsea have confirmed Morocco winger Hakim Ziyech has completed a permanent transfer to Galatasaray following a loan spell with the Turkish club.