JOIN USMarsh is the sixth Australian to have been given the job of coaching Sri Lanka after Dav Whatmore, John Dyson, Tom Moody, Trevor Bayliss and Stuart Law.
Marsh joining the island nation means he will no longer be involved with coaching Indian Premier League franchise Pune Warriors.
"I told Pune Warriors and they were very good about it. Coaching an international team takes a lot of time and being able to fit both of them in just wouldn't have happened," Marsh was quoted as saying by ESPNcricinfo Friday.
"They (Pune) are very comfortable with it. I enjoyed my year at Pune Warriors. They are a fantastic family. They could see that coaching an international team is an honour, so it was all good."
Marsh's appointment ends a period of uncertainty in Sri Lankan cricket which saw Bayliss stepping down after the World Cup final and Law shifting base to Bangladesh after the England tour.
Rumesh Ratnayake was in charge in Sri Lanka's recently concluded home series against Australia.
Marsh played 50 Tests and 119 One-day Internationals for Australia, and was a member of the World Cup winning side in 1987.
He is the only cricketer to have won both the World Cup as a player and a coach, the latter happening in the 1999 edition.