The Greek-born Australian coach was announced as the club's new head coach this morning - 105 days on from the departure of Neil Lennon - on a 12-month rolling contract.
He leaves Japanese top flight side Yokohoma F.Marinos, having previously managed Melbourne Victory and Brisbane Roar, as well as the Australian national team.
He has won several titles with his previous clubs, however, his lack of experience coaching in Europe appears to be a factor in putting doubts into the minds of Celtic fans.
Some are already questioning the appointment, while others are prepared to back the club's decision.
Here is a selection of supporter reaction on social media:
Electronic Tims (@ETimsNet): Doesn’t make any sense whatsoever. None. Nada. But..he’s the new mgr & merits our support (initially at least!) as the amateur & shambolic behaviour of the board is nothing to do with him. I genuinely hope Ange is a resounding success & makes many fans like myself eat our words.
Chris (@RodneyFarmer): A reckless gamble. Really the best we could get? Doubt it. Board embarrassing themselves again.
TC (@TCCSC93): Nervous with this appointment as we havent got a clue what to expect but as always whoever gets the job has my full support. Time to get the rebuild started Ange and time to prove everyone wrong
James McVey (@JjJ271267): Brilliant news, as a diehard Celtic fan living in Melbourne I reckon this is a fantastic appointment by Celtic. A real football man who lives and breathes the game. Well done Celtic and welcome Ange
Celtic FC Supporter (@8881CFcitleC): At the point were this is just meh! whatever! as it has took so long. No DoF, No Head of Recuitment, Players leaving, no sign of quality coming in, likely no quality players coming in just bargain basement hopefuls. Wish him well but enthusiasm is gone
Johnaldinho (@karmabusdriver): As an Australian Celtic fan, I'm thrilled to see a number of people backing Ange. The Board is a mess, and for that, don't blame Ange. He will bring energy and passion, an attacking style of play. Hope the players are coachable. This will be a hell of a season ahead.
Mike McV (@mmcveighbhoy7): The 12 month rolling contract, says it all. He does well and he's off, not so well he's off. Surely if you believed in this appointment he would be tied down and allowed time to build.
Jason Maloney (@maloney_jason): Get the feeling he'll either end up a cult hero or a complete flop. But all we can do is get behind the man. Looking forward to seeing his style of football but he's some job on his hands. Welcome Ange.
Marc McArdle (@marcmcardle1): The club have sucked all joy out of what should’ve been an exciting new start through their own incompetence. But at least we’ve finally got somebody in the door. They now need to throw together a recruitment network for him somehow and sign half a squad in a month.