They had been captured in two separate incidents in June last year while covering the conflict in Syria.
Footage of the journalists broadcast on Turkish television showed them looking unkempt, with beards and long hair, but they appeared to be in good health.
"I'm very happy to be free," said 53-year-old Francois. "We thank the Turkish authorities because they really helped us. And it's very nice to see the sky, to be able to walk and to be able to speak freely."
The Turkish soldiers initially took them for smugglers but took them to a police station in the small town of Akcakle near the border when they realised they were speaking French.
Around 30 foreign journalists covering the Syrian civil war have been seized since the conflict began in March 2011, and many are still missing.
Hollande told AFP he had learnt of the liberation of the four Frenchmen "with immense relief".
"I share the joy of the families of our compatriots who have endured... the fear of this trying time," Hollande said.
- Failed escape attempt -
Francois, a highly respected and experienced war reporter for Europe 1 radio, and photographer Elias, 23, were taken north of the main northern Syrian city of Aleppo on June 6.
Henin, a 37-year-old reporter for Le Point magazine, and freelance photographer Torres, 29, were seized two weeks later also in the north of the country, at Raqqa.
"FREE!!!" Henin wrote on his Facebook page. "A huge thank you to everyone. I am very moved by your messages. Can't wait to see you again. I am ecstatic to be able to rejoin my wonderful family."
The reporter said he had managed to escape once, but was recaptured.
"I took the biggest risk three days after my kidnapping, because I escaped. I spent a night in freedom running through the Syrian countryside before my kidnappers caught up with me," Henin told France 24 television.
Describing the captors as "a group that claims to be a jihadist movement", the journalist said he was transferred to about a dozen different sites during the months spent in captivity.
Recounting the last hours before he was freed, Henin said: "Usually we were not very well fed. But the guards came to our cell and brought us a meal that was better than the usual, and even asked if we wanted to eat more, which never happens.
"So we thought: something's going on. And quite rightly, as we hardly had any time to eat before they came in the next minute to say 'let's go, we're going to the border'", he recalled.
- 'Immense joy' -
The four men are expected to arrive in France overnight, with their plane having departed from south-east Turkey at around 2000GMT.
The ex-hostages will return to an immense outpouring of joy and relief from family and colleagues.
"We don't know what to say, we are very happy obviously, but we are completely overwhelmed," Elias's grandmother Josette Dunand told AFP.
Henin's father Pierre-Yves Henin told AFP the men were "about to get on a plane to come back", and that their morale was "particularly good".
The head of Europe 1 Denis Olivennes described emotional scenes in the office.
"It is an immense joy, we are in tears," he said. "We have endured 10 months of terrible anxiety and anguish. Now they are freed, I have no words to describe how it feels."
There had been some indication that a release was possible in recent days.
"We were told a few days ago that they had a window of opportunity, but we have learned not to get our hopes up," said Fabien Namias, chief executive of Europe 1.
"For some time, we had regular news every three weeks that they were being held together, not isolated, that they had not been treated too badly. And they are in good health -- that's the main thing."
The four men's liberation comes weeks after two Spanish journalists taken hostage in Syria in September by an Al-Qaeda-linked group called the Islamic State of Iraq and the Levant also walked free.
Hollande said his attention was now with two other French citizens still held in the Sahel region of Africa, reaffirming his determination to obtain their release.
Among those still being held in Syria are US journalist James Foley, who had been working for Global Post, Agence France-Presse and other international media and went missing in November 2012, and Austin Tice, who disappeared in August the same year.
The New-York based Committee to Protect Journalists said in a report Wednesday that Syria was the most dangerous country for journalists, highlighting a rising number of "targeted killings" of reporters.