New challenge for Wigan Athletic old-boy
Caldwell was sacked by Latics exactly two years ago, before overseeing an ill-fated 29-game spell at Chesterfield.
“The appointment of Gary comes at the end of a rigorous selection process, which we believe has resulted in the best candidate for the job being named as our new manager,” said Partick chairman Jacqui Low.
“Gary is a driven individual with a clear vision and plan to succeed - a new face our rivals may not expect and will not be prepared for.
“The board also wanted to bring in someone the players would respect for his achievements.
“With his track record both as a player and as a manager, we believe Gary is that man.
“We were blown away by Gary’s interview preparation and, in the space of a week, he had done an analysis of each player, identified a training schedule to deal with the fitness levels and pulled together a vision of how to get Thistle playing well enough to secure promotion.”
Caldwell added: “There is a huge amount of potential in this squad. But it won’t happen overnight.
“We can’t do it on our own either, I need support from the fans and so do the players.
“If we are together, I have no doubt we can achieve a massive amount.”