The 16 year old has signed a three-year deal and will link up with Villa's promising youth team.
The Claret and Blue have relied heavily on the youth set-up in recent years, which has produced stars such as Gabby Agbonlahor and Craig Gardner.
Dau will hope to make an impression at the club and learn from talented keepers such as Scott Carson and Tommy Sorensen.
He impressed on a two-week trial and will be delighted to have earnt himself a full contract at the club.