Villa land Makoun from Lyon
Makoun came to prominence at Lille, where he made nearly 200 appearances over six seasons, attracting interest from several sides across Europe, including Juventus and Arsenal.
He ultimately moved to Lyon in 2008, where he has continued to impress both domestically and in Europe - scoring the Ligue 1 side's winning goal in the home leg of last season's Champions League Last 16 victory over Real Madrid.
"Villa have been after me for quite a while, so I am delighted it's finally happened. I can't wait to get started now", the 27-year-old midfielder said on the club's offical website.
"I've left a very good club in Lyon, a side which has played Champions League football, but I am very excited by this new challenge at Aston Villa. Villa really want to do well and really want to achieve something, so I am really excited to be joining."
Speaking of his first acquisition as Aston Villa manager, Gerard Houllier said; "Jean is a player who can play in front of the defence as a sitter and defensive midfielder or as a box-to-box midfielder. He has several assets about his game. He is also a very experienced player because he played Champions League football with Lille and Lyon."
Makoun will be eligible to play once he has received a work permit, a process that could take up to two weeks, according to his new club.