Ronny Deila has been named as the new manager of Celtic on a 12-month rolling contract.
The Norwegian, 38, takes over from Neil Lennon, who left the Scottish champions shortly after securing his third title in a four-year spell.
Deila guided Stromsgodset to the Tippeligaen title last season and won the Norwegian Cup in 2010.
"I will treasure this opportunity and will give everything I have to achieve success for Celtic," said Deila.
"It is a magnificent honour to be named the new manager of Celtic, one of the world's great football clubs and a club I have such enormous respect for.
"I know what I want for Celtic and our supporters and that is the best of everything, it is what our fans deserve.
"I want to deliver the best attacking, exciting and entertaining football we can play, for the players to give their best every time they take to the field of and, of course, I want my players to work with me to achieve the best results possible and bring trophies to Celtic.
"Celtic is in great shape and the club has enjoyed real success in recent years due to the hard work of Neil and his team.
"I want to carry on this work and continue to bring happy times to Celtic. I can't wait to get started on this journey."
Deila took charge of Stromsgodset in 2008 following a period as a player and assistant manager at the Drammen club.
He leaves with Stromsgodset sitting second in Norway's top flight, five points behind Molde, but his farewell was a disappointing 4-2 loss to second-tier outfit Tromsdalen in the Norwegian Cup on Wednesday.
Celtic chief executive Peter Lawwell told the club website: "We believe Ronny will prove to be a fresh and dynamic new manager and someone who will give us a bright and energetic way forward for Celtic.
"Knowing that he was so highly-rated across Europe, Ronny was one of the first candidates we considered as manager.
"Having discussed the opportunity with him at length, we are convinced he has the talent and the determination to deliver very positive results for the club and our supporters.
"Ronny likes to play attacking, winning football, the Celtic way, something I know our supporters will endorse."
Lawwell later added that the Norwegian was considering "three or four options" for an assistant coach.
Earlier this week, Roy Keane ruled himself out of the running to be manager, with the 42-year-old continuing his role as Republic of Ireland assistant coach after informal talks with Celtic majority shareholder Dermot Desmond.
Former Celtic striker Henrik Larsson committed himself to Swedish club Falkenbergs following an approach, while former West Brom manager Steve Clarke and ex-Wigan and Bolton boss Owen Coyle were among others linked with the vacancy.
John Hartson, who played for Celtic between 2001-06, was certainly taken aback by the appointment.
"I don't know anything about him other than what I've looked up on Google," he told BBC 5 live. "I'm surprised just like a lot of Celtic supporters all around the world.
"I'm all for people getting a chance. He may not be the big name that a lot of fans wanted, but they will back him. It's not always the star names that are the best appointments."
Celtic begin their next campaign on 15/16 July with a Champions League qualifier against an as yet unconfirmed round-two opponent.