The centre-back, 30, has joined the Trotters on a season-long loan deal with a view to a permanent transfer.
The two clubs had been unable to agree a fee for the long-serving defender, who was keen to remain in the Premier League following the Baggies' relegation to the Championship.
Robinson previously worked under now Bolton boss Gary Megson at The Hawthorns.
"He's got a great deal of Premier League experience and is the type of player Wanderers supporters will like," Megson told the club's official website.
"He has a wholehearted approach to the game, is desperate to win and will be good in the dressing room.
"I signed Robbo for West Brom from Watford a good few years ago and I know him really well."