Boateng was born in Ghana, and began his footballing career in Holland, at Feyenord. In 1998, he moved to Coventry, before joining Aston Villa for £4.5 million in 2000. At Villa, he played in the 2000 FA Cup final defeat to Chelsea. He later moved to Middlesbrough, where he captained the club, and won the League Cup in 2004, and was a runner up in the 2006 UEFA Cup. Boateng played 4 times for Holland between 2001 and 2006.