Mouyokolo is available on a free transfer after leaving Wolves in January following an injury-hit spell at Molineux.
Celtic boss Neil Lennon and his coaching staff will now cast an eye over the 26-year-old in training as they weigh up a move for the centre-back.
Celtic coach Danny McGrain confirmed the Frenchman was training with the Scottish champions.
"He's here until the end of the week. He doesn't look strong but he's tall with a good physique," he said.
"He's not a Bobo Balde type. But we haven't had a game situation yet, defending corners and free-kicks."