"I think we lose and we will miss a great champion on the track. He beat all the records so he has the best numbers in Formula One but I think maybe F1 will focus more on sport after that."
Schumacher has split opinion throughout his career
Fernando Alonso, F1 world champion
"Where Schumacher cannot draw the right line is on track. He cannot see when he crosses the line between tough but fair, and ruthless but foul.
"That is exacerbated by his total belief that he cannot be wrong. He has a default mode in the car: if you're going to pass him, he will drive you off the road. He even did it to me as a team-mate."
Martin Brundle, former Benetton team-mate
"If the best guy in the world retires it is certainly a sad day. You can say whatever you want, he won seven world championships and he might win another one. There is nobody like him in the world, he is unique."
Niki Lauda, triple F1 world champion
"He's been in it long enough and achieved everything. His records will never be broken probably. So I think it's time to give some space for younger boys."
Former F1 driver Mika Salo, who stood in for Schumacher when the German broke his leg in 1999
"He's done some fantastic drives, he's made some stupid mistakes. He's not a great in my mind like [Juan Manuel] Fangio, but is one of the most talented drivers."
F1 legend Stirling Moss
"People have said to me that F1 is boring because he wins everything. So presumably when he's not here, people will be happy. But we'll miss him, because he is a superstar."
We will miss him a little bit as a driver, we will miss him a lot in the football matches
Bernie Ecclestone, Formula One boss
"Everybody will miss Michael, whoever they are. It is a big event for everyone. I think someone of his ability, someone of his experience, and someone of his involvement will be very badly missed. But F1 goes on, Ferrari goes on."
Ross Brawn, Ferrari technical director
"Michael has been the author of a unique chapter in the history of Formula One and he is a great friend."
Jean Todt, Ferrari managing director
"The last stars I saw in F1 were (Ayrton) Senna and, even if he won only one world championship, Jacques Villeneuve. If we want, we could also add (Juan Pablo) Montoya. Now, instead, we have only champions."
Flavio Briatore, Renault boss, who led the Benetton team with which Schumacher won his first two titles
"On one hand we will miss him as he is the complete driver and we have a great relationship. On the other hand, every driver wants to be in his postion with seven world titles in his pocket. Great drivers retire and others come - hopefully I can be one of these.
Ferrari team-mate Felipe Massa
"Michael is the most experienced driver and he has achieved the most so it is good to have someone like him involved. But he will leave and someone will take his place and it will still be competitive."
Honda driver Jenson Button
"It is a pity for F1 to lose such a great champion, but the time to stop comes to everyone."
Gerhard Berger, former Ferrari F1 driver
"We will miss him a little bit as a driver. We will miss him a lot in the football matches."
Jarno Trulli, Toyota driver
"Any top driver when he leaves will be missed. Michael's probably the furthest up the scale of anyone because he's got an unbeaten record. It won't damage F1 in any way but I think all of us who follow it will miss him clearly because he is an exceptional driver."
Max Mosley, president of governing body the FIA
"He has everything to lose and nothing to gain, so it's very logical and sensible to retire while he's on top of his game, but knowing Michael, everything he has been able to do, I think he would still have the energy to continue."
Alex Zanardi, former F1 driver and double Champ Car champion
"He should be able to sleep comfortably in his bed now."
Jackie Stewart three-time world champion
"He has broken every record in the book, has money in the bank, a loving family and lots of lovely homes but it will be very, very difficult for him to find a replacement in his life for what Formula One has given him."
Murray Walker, former television commentator