Ambitious Aiden Headridge, from Dundee, sent a letter to the club’s chief executive Peter Lawwell asking if he could fill departing boss Neil Lennon’s shoes.
The Headridges today received a reply from Lawwell - along with a Celtic shirt.
Lawwell’s letter to the youngster thanked him for taking the time to write to him but informed him the club had decided on a more experienced manager.
It said: “As you will know, we have appointed Ronny Deila as the new football manager.
“I believe Ronny has the knowledge, enthusiasm and confidence that is necessary to take the club forward and deliver continued success.
“I am really pleased to learn that you would like to be the Celtic manager and maybe one day that will happen.
“In the meantime, I hope you are enjoying school and are looking forward to the summer holidays.”
Aiden’s older brother Ciaran, 21, then caused an online storm posting a picture of the letter and the shirt onto Twitter.
He tweeted: “My 6yo brother wrote to @celticfc about becoming new manager, and club sent this back. Will put a smile on his face!”
His message was retweeted over 600 times and favourited by more than 400 users of the social network.
Speaking yesterday before Aiden had finished his school day at St Peter and Paul Primary, his mother Lynne (corr) Headridge, 37, said that Aiden will be jumping through hoops when he sees the response.
She said: “He hasn’t seen the letter yet but he will be bouncing off the walls when he does.
“He’s a crazy-mad Celtic fan, it’s all I ever hear about - Celtic this, Celtic that. He’s obsessed.
“When he wrote the letter we thought that we’d just indulge him a bit, he loves them so much he thought he could do a good job at managing them.
“We didn’t expect a reply never mind a shirt too.”
Lynne said that if Aiden can’t manage his beloved Celts he hopes to put on the hooped top himself and take to Parkhead.
She said: “He really just wants to play for Celtic - it’s all I’ve ever heard him talk about doing.
“It’s amazing that a club the size of Celtic still takes time for its littlest fans like Aiden.
“He goes to the matches quite a lot but I imagine that you’re quite anonymous there. It will feel really personal to him when he sees the letter.
“I don’t think he’ll ever take the shirt off- he’ll probably watch it spinning around the washing machine until he can wear it again.”