Charité Hospital said it was ending acute medical care because his condition had improved enough.
Mr Navalny posted a photo of himself on social media unaided with a message saying doctors have given him every chance of a full recovery.
Germany claims that Mr. Navalny, critic of President Vladimir Putin, was poisoned by a Novichok nerve agent.
He collapsed in a flight from Siberia on August 20 and was transferred to Charité hospital in the German capital.
His team claims he was poisoned on the orders of President Putin. The Kremlin denies any involvement.
A statement from the hospital said Mr. Navalny, 44, spent 32 days there, including 24 days in intensive care.
“Based on the patient’s progress and the current condition, treating physicians believe a full recovery is possible. However, it is still too early to assess the potential long-term effects of his severe poisoning, ”he said.
Earlier this month, the hospital revealed Mr Navalny had started to recover, claiming he was taken off a ventilator and was able to get out of bed.
At the time, the German government said labs in France and Sweden reconfirmed German tests showing the poison used on Mr Navalny was a Novichok agent.
The Kremlin said there was no evidence of this.
In an Instagram post on Tuesday, Mr Navalny dismissed suggestions – allegedly from President Putin – that he had poisoned himself.
French newspaper Le Monde reported that in a telephone interview with President Emmanuel Macron on September 14, Mr. Putin spoke “with contempt of Alexei Navalny, seeing him as a simple Internet troublemaker who had faked diseases in the past ”.
“Putin foiled me,” Navalny wrote on Instagram, mocking the Russian president. “He’s nobody’s fool. As a result I, like a fool, spent 18 days in a coma but failed to achieve what I wanted. The provocation failed! “