The 29-year-old forward, who has been at Leverkusen since 2006, topped the Bundesliga scorers' list last season with 25 goals in 34 games to help Leverkusen to third place and a Champions League spot.
"Stefan Kiessling is a top player, leader and face of Bayer Leverkusen," club general manager Wolfgang Holzhaeuser said in a statement.
"He has certainly been my top transfer. His development since 2006 has been phenomenal and I hope he will end his career with us."
Leverkusen have been eager to hold on to their forward, especially after team mate Andre Schuerrle departed for Chelsea in June.
Kiessling, whose club turned down several offers for him earlier this year, has been consistently overlooked by Germany coach Joachim Loew, having won the last of his six caps in their 2010 World Cup third-place victory over Uruguay.