Martin O'Neill won 19 of his 55 matches in charge of the Republic of Ireland
Nottingham Forest say club legend Martin O'Neill is "realising a lifelong dream" after he was appointed as manager of the Championship club.
The 66-year-old, who played 371 games and won the European Cup as a Forest player, ended his five-year spell as Republic of Ireland boss in November.
Forest are ninth in the table, four points outside the play-off places.
O'Neill has succeeded Aitor Karanka at the City Ground and is Nottingham Forest's 11th manager since June 2011.
The length of the former Aston Villa and Leicester manager's contract has not been disclosed.
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Karanka's exit from the City Ground - with Forest still very much in the promotion race - means O'Neill arrives in a strong position both on the field and off it.
After finishing 17th in 2017-18, they invested heavily during the summer, with Joao Carvalho arriving from Benfica for a club record fee of £13.2m and striker Lewis Grabban joining in a £6m deal from Bournemouth.
The Forest job is the Northern Irishman's first return to club management since a mixed spell with Sunderland, which saw him guide the Black Cats away from relegation from the Premier League in his first season but then struggle again the following campaign prior to his sacking in March 2013.
Analysis
BBC Radio Nottingham's Colin Fray on BBC Radio 5 live
It's not been unanimously well greeted and there are a few who have reservations, but the majority of Forest fans seem to be in favour.
Clearly there's a danger it could be a sentimental appointment given O'Neill's previous connections with the club, but I think there's far more about it than that.
They've looked at his record as a club manager which, right from Wycombe Wanderers and through, has been exemplary.
When they play Bristol City at home on Saturday, the atmosphere will be tremendous as he's welcomed home almost.
Source: bbc.com