McLeish handed Forest reins
Fenerbahce midfielder Raul Meireles has had his 11-match ban reduced to four matches on appeal, the club have confirmed.
The former Chelsea player was hit with the suspension after being accused of spitting at the referee following his red card in the Istanbul derby with Galatasaray.
But the Turkish Football Federation's disciplinary committee ruled the Portugal international did not deliberately spit at Halis Ozkahya.
It said it was "physically impossible" for him to have spat as he berated the referee for his sending-off as he was speaking throughout the incident.
The 29-year-old will still have to serve a four-game ban because of his verbal attack on the referee.
Meireles, who joined Fener from Chelsea in the summer, had vehemently denied the accusations and vowed to prove his innocence.
The former Birmingham and Aston Villa boss will begin work on Friday and will take charge of Saturday's Championship encounter with Crystal Palace at the City Ground.
"I'm delighted to welcome Alex to our club and look forward to working with him," Forest chairman Fawaz Al Hasawi said on club website nottinghamforest.co.uk.
"Alex took Birmingham to promotion from the Championship and has great experience of working in the Premier League.
"He's hungry for more success and I believe he's the man who can help us fulfil our ambition of making it to the Premier League."
The 53-year-old McLeish, who has also had spells in charge of Rangers and the Scotland national team, had been out of work since being dismissed by Villa in May, after finishing just two points above the relegation zone in the Premier League.
The Scot, who will be presented to the media following training on Friday morning, welcomed the opportunity to return to management at a club lying eighth in the second tier.
"I'm really looking forward to working with Nottingham Forest," McLeish told Forest's website.
"I've had time away from the game and now feel refreshed and ready to go.
"The fact that a club of Forest's magnitude has offered me a job excites me greatly - it's a wonderful opportunity.
"I can't wait to get started and I'm looking forward to meeting the players, talking to them and taking my first training session."