Mohammed Camara has become Gordon Strachan's first signing as Celtic boss after agreeing a two-year deal.
Mo Camara is out to prove his worth to the fans
The Guinea left-back, who rejected a new deal with Burnley and an approach from Ipswich Town, put pen to paper after undergoing a medical on Tuesday.
Camara, 30 on Saturday, said: "Celtic is an absolutely massive club for me.
"I know I am not from a big club and I am not a big-name player and that's why I'm desperate for the season to start, so fans can see I deserve this shot."
Camara joined Wolverhampton Wanderers from Le Havre for £100,000 in 2000 before moving to Burnley in 2003.
He had been lined up by previous Celtic manager Martin O'Neill, who stood down last month to spend more time with seriously ill wife Geraldine.
The left-back position had proved troublesome during the Northern Irishman's successful time in Glasgow.
And Ipswich fell out of the running for his signature when they failed to win promotion to the Premiership in England.
"When I heard about Celtic`s interest, I was willing to wait for a long time because, for me, coming here is like a dream come true," said Camara
"My life is unbelievable at the moment.
"I just want to come in now and prove myself and fight for my place."
Camara admitted that he had sought the advice of Rangers midfielder Alex Rae, a former team-mate at Wolves, who made him aware of the rivalry between the clubs.
Strachan told his club's website: "He's got pace, he's got enthusiasm and he's got experience now.
"If we can sign someone of this quality on a Bosman, we have to take it."
Camara could be joined at Celtic Park by striker Maciej Zurawski, who hopes to seal a £2.2m move from Wisla Krakow.
Celtic chief executive Peter Lawwell added: "We are hopeful that Mo will be the first of a number of new players to join the club over the transfer window."