Bayern sign Mainz defender Kirchhoff
The 22-year-old, who is out of contract at Mainz this summer, has penned a deal until 2016 and will join up with the record German champions at the end of the season.
Kirchhoff, who is likely to be a member of Germany's Under-21 squad for the European Championships later this year, joins on a free transfer.
"We are really pleased that such a highly talented Under-21 international has decided to join Bayern," Bayern chairman Karl-Heinz Rummenigge told the Bild newspaper.
Kirchhoff has made over 50 Bundesliga appearances for Mainz since arriving from Eintracht Frankfurt in 2007.