Martin O'Neill has left his post as manager of Nottingham Forest, the Championship club have announced.
The 67-year-old - who made 371 appearances for Forest as a player, winning two European Cups - returned to the City Ground as boss in January.
Nottingham Forest have announced that Sabri Lamouchi has been appointed as the club’s new head coach.
Former Republic of Ireland manager O'Neill guided the club to a ninth-placed finish in the Championship last term, but his short-lived tenure is now over.
A statement on the club's website read: "Nottingham Forest can confirm that manager Martin O'Neill has left the club.
The club would like to thank Martin for all his efforts during his time at The City Ground and wish him well for the future.
O'Neill's assistant Roy Keane left the club on Sunday and reports have suggested player unrest is behind the former Celtic boss' departure.
The Northern Irishman took charge with Forest in ninth place but he failed to guide the club into the play-offs.
Forest have not played in the top flight since 1999 and Sabri Lamouchi will be their 12th manager since June 2011.
Lamouchi led the Ivory Coast to the 2014 World Cup as the top-ranked side in Africa and the quarter-finals of the 2013 African Cup of Nations, and won the Qatari Cup and reached the Asian Champions League semi-finals during his time at El Jaish SC.
Most recently, he was in charge of Rennes in Ligue 1, taking them from the relegation places to qualify for the Europa League in 2017-18.
As a player, Lamouchi made over 470 appearances for clubs such as Monaco, Parma, Inter Milan and Olympique Marseille as well as appearing 12 times for the French national team.
According to the club, he will be assisted at Forest by six new members of staff who will support the first team.