Murray was set to begin working with Lendl immediately, ahead of preparations for the Australian Open.
“Ivan’s impact on the game is unquestionable and he brings experience and knowledge that few others have, particularly in major tournaments,” Murray said.
Andy is a unique talent, and I look forward to trying to help him reach his goals
“It was important to me that any new person joining my team was able to add fresh insight.”
Czech-born Lendl won eight grand slam tournaments during a stellar playing career.
Lendl said: “I am really excited to have the opportunity to work with Andy.
“Andy is a unique talent, and I look forward to trying to help him reach his goals.”
Murray experienced a mixed year in 2011, enjoying a spell at world number three before dropping back behind Novak Djokovic, Rafael Nadal and Roger Federer.
He reached the final of the Australian Open and the semi-finals of the other three grand slams, and enjoyed a rich run of form later in the year, lifting titles in Bangkok, Tokyo and at the Shanghai Masters.
But his season ended with disappointment, pulling out of the Barclays ATP World Tour Finals in London with injury.