The French World Cup winner scooped two FA Cups plus a League Cup, a Cup Winners' Cup and a Super Cup during his successful five-year stay at Stamford Bridge.
However, the former defender reckons current Blues boss Mourinho has a special relationship with his players which few other managers enjoy.
"He has a great character," said Leboeuf.
"I've seen many players who weren't in the first XI loving Mourinho - and that's the first time players on the bench don't hate the coach! I've seen players like Marco Materazzi, when Mourinho left Inter Milan, he cried. That's something special. That guy is loved by all the players.
"I love the showman but what he does is protect the players as well. Between the two legs against Paris Saint-Germain everyone was talking in France about Mourinho, nobody talked about the players; there was no pressure on the players."
Leboeuf never lifted the Premier League trophy whilst with Chelsea but reckons his old club can still win the 2013/14 league.
However, he admits he's been impressed by the challenge from Liverpool and reckons Manuel Pellegrini's Manchester City are currently best placed to take the title.
"Chelsea can win the title. I'm very positive about that," he said.
"They're not alone, though. Liverpool are really amazing right now, with their lower budget and smaller squad they're doing great. I'm very pleased for Brendan Rodgers, too. Before he signed I said he was the perfect guy for Liverpool.
"But Manchester City are in a better position than the other two teams."