Müller has a wife named Katia and has two children, daughter Norah (born 30 April 2004) and son Dan (born 5 March 2006).
Müller ka një grua me emrin Katia dhe dy fëmijë, bijën Norah (e lindur më 30 prill 2004) dhe djalin Dan (i lindur më 5 mars 2006).