Mr Ross has worked in the health service for 45 years and took up the post of acting chief executive in April 2012.
He was appointed to the post of chief executive in December 2012.
Health Secretary Alex Neil said: "I would like to extend my sincere thanks to Ian for his dedication and commitment to Scotland's NHS.
"With a remarkable 45 years of service in the NHS, Ian brought a wealth of experience to his role as leader of NHS Lanarkshire.
"Ian's commitment to the NHS never faltered, and I'm sure he will be deeply missed by the staff of NHS Lanarkshire."