The player is now expected to undergo his medical with the Premier League club and finalise personal terms.
The 23-year-old was heavily linked with a move to the Premier League this summer, and the West Midlands club will be delighted to have secured his services.
Bailey was one of the best attackers in the Bundesliga last season, and he could prove to be a sensational signing for Dean Smith’s side.
Although Bailey is a different type of player, he could fill the creative void left by Grealish next season.
The 23-year-old Jamaican scored 15 goals and picked up 10 assists across all competitions last season.
The Bayer Leverkusen star is yet to reach his peak, and there is no doubt that he will improve further with experience.
Bailey has the potential to develop into one of the best attackers in the Premier League, and it remains to be seen whether he can adapt quickly and make an immediate impact at Villa Park next season.
Villa have also signed the likes of Emiliano Buendia and Ashley Young this summer.
It will be interesting to see if they can add a quality striker to their ranks before the window closes.