Keller had taken charge of the side on 16 December 2012 following the dismissal of previous incumbent Huub Stevens, and was tasked with steadying the ship until the end of the present Bundesliga campaign. His contract renewal comes hot on the heels of Julian Draxler also agreeing fresh terms with the Royal Blues.
"Jens came in during an extremely difficult time for the club last December," said sporting director Horst Heldt. "In the face of significant obstacles, including from the public, Jens never deviated from his plan and brought Schalke back on track in the Bundesliga."
Indeed, having hauled the side out of a form slump during which they had slipped to seventh place over the winter break, Schalke are on the brink of securing fourth spot and a UEFA Champions League qualifying berth. The achievement is all the more noteworthy given long-term injuries to key players such as Kyriakos Papadopoulos, Ibrahim Afellay, Klaas-Jan Huntelaar and Jefferson Farfan.
"We like the way Jens works," continued Heldt. "Despite the personnel difficulties of the past few months we've seen some obvious progress. Jens' philosophy is very clear and everyone at the club, from players right up to the key decision-makers, are happy with his work."
As a player Keller laced up his boots for Stuttgart, 1860 Munich, VfL Wolfsburg, 1. FC Köln and Eintracht Frankfurt, scoring twice in 142 Bundesliga games and netting a further six goals in 115 Bundesliga 2 appearances. He was Under-17 and Under-19 coach at Stuttgart between 2007 and 2009, before becoming assistant coach at the Swabian outfit later that year and taking full charge of the side in 2010/11. Before his appointment at Schalke, Keller was a youth team coach with the Royal Blues.