The 27-year-old has been a free agent since his contract with Barclays Premier League rivals Aston Villa expired.
Reo-Coker has agreed a two-year contract with the Reebok Stadium club.
On the move: Nigel Reo-Coker (left) was released by Aston Villa this summer and has now joined Bolton
Reo-Coker told Bolton's official website: 'I spoke with the gaffer and he outlined his plans and how he wants the club to progress.
'I want to be part of that and I'm looking forward to meeting up with the lads and getting to work.'
Bolton boss Owen Coyle said: 'We're delighted to have signed Nigel.
New boy: Reo-Coker (right) also played for West Ham and joins fellow summer signing Darren Pratley at Bolton
'He's got the quality, drive and desire to compete at the highest level in the Barclays Premier League and I'm delighted that we have beenable to bring him to the club.'
Croydon-born Reo-Coker, who joined Villa for ?8.5million from West Ham in 2007, started his career with Wimbledon.
He was named captain by Gerard Houllier in the absence through injuryof Stiliyan Petrov - and becomes Bolton's second signing of the summer,former Swansea midfielder Darren Pratley being the other.
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