Merkel declared herself "extremely shocked along with millions of Germans" by the news, according to her spokesman Steffen Seibert.
"We hope, along with Michael Schumacher and his family, that his injuries will heal and he will recover. We wish his wife, his children and the rest of his family strength and mutual support."
Schumacher's wife Corinna and the family expressed their gratitude for the encouragement.
"We would like to thank the medical team who, we know, do everything possible to help Michael," she said in a statement. "We (would) like to also thank the people from around the world who have expressed their sympathy and sent their best wishes for his recovery."
Formula One quadruple world champion Sebastian Vettel, 26, who has said Schumacher was his childhood idol, said: "I am shocked and I hope that he'll be feeling better as soon as possible. I wish his family much strength now."
Other well-known German sporting stars took to social media wishing the racing legend known as "Schumi" a quick recovery.
Tennis legend Boris Becker wrote on Twitter, "Let us all pray for (Schumacher) for a full and speedy recovery !!!", while basketball star Dirk Nowitzki wrote, "My thoughts are with Schumi".
The 22-time Grand Slam winner Steffi Graf wrote on Facebook that "our worries and thoughts are with Michael 'Schumi' and those who are close to him.
We wish him a speedy recovery and know that his strength will help him through
this difficult situation".
Under the Twitter hashtag #KaempfenSchumi (Fight, Schumi!) many others sent their wishes, including: "Schumi, you must win this race too! It's your most important yet."
Across Germany, fans were anxiously awaiting the next update on Schumacher's condition and the media was awash with the news. "We're very upset. We know him really well. He's a fighter, we're crossing fingers that he will win this battle," said Michael Viehmann, president of a Schumacher fan club in Kerpen, where the retired racer grew up.