First Lady Valerie Trierweiler left the Paris hospital, where she had been admitted on January 10 suffering from nervous exhaustion and low blood pressure, for a presidential residence in Versailles, a source in her office told AFP.
In her first public comments since the scandal over Hollande's affair broke, Trierweiler tweeted her thanks to her supporters.
"Thank you from the bottom of my heart to all those who sent messages of support… very touched," she wrote, using her personal and not her official Twitter account.
Concern had been mounting for Trierweiler, 48, after she fell ill following the revelation that Hollande, 59, had been having an affair with 41-year-old actress Julie Gayet.
Paris Match magazine, Trierweiler's employer, said Friday that her family was "worried" after her 16-year-old son Leonard was unable to visit and she did not take calls.
But he was reunited with his mother after she left hospital, tweeting, "finally with my mother! I am happy to be back with her".
In a report Saturday the magazine said the First Lady had seen "almost no one" during her stay at the Pitie-Salpetriere hospital.
Merci du fond du cœur à tous ceux qui ont envoyé des messages de soutien et de rétablissement via twitter, SMS ou courriels. Très touchée.
— Valerie Trierweiler (@valtrier) January 18, 2014
There, she built up her strength eating jambon-coquillettes — a hearty dish of macaroni cheese with ham — a change from the dainty nouvelle cuisine at the presidential palace, it said.
Hollande, who did not visit Trierweiler in hospital until Thursday and has dodged questions regarding the couple's future, was Saturday on a visit to his political stronghold of Correze in central France.
In a speech in the town of Tulle he again did not comment on the revelations, focusing instead on local issues.
But even longtime allies were saying the president needed to deal with the scandal.
"France's political situation requires all of the president's attention and all of his time, so obviously it would be best for everyone if he can resolve the problems in his personal life under good conditions," said Tulle Mayor Bernard Combes, a member of Hollande's Socialist party.
At restaurant La Taverne du Sommelier, where Hollande has a permanent table, owner Cecile At said the president needed to put the scandal behind him.
"Francois Hollande is a very friendly man but Madame (Trierweiler) kept her distance, she did not seek people out," At said.
"The time has come for our president to make decisions on his personal life and for the debate to be closed — that there be no more rumours or photos."
Hollande has said he will clarify his relationship with Trierweiler before a trip to Washington next month but has refused any further comment on a scandal that has generated global headlines.
In his first trip outside Paris since the scandal broke, Hollande focused mainly on rural issues, saying he opposed calls to do away with some local administrations.
There was rare media interest for the trip to regional France, with dozens of French and foreign reporters descending on the small community for Hollande's speech.
On previous trips to the region Hollande had regularly visited the Tulle market — often accompanied by Trierweiler — but he skipped it this time.
Reports have emerged that Hollande took Gayet to the Tulle market during his last visit to the region in July.
Closer magazine reported last week that Hollande had been having secret trysts with Gayet and published photographs of the pair arriving separately at a borrowed flat near his official residence, the Elysee Palace.
The scandal overshadowed a major policy speech by Hollande vowing new economic reforms and raised questions about whether he had misled the public
or put his personal security at risk.
Hollande's failure to visit his partner in hospital until Thursday fuelled speculation that he has decided to end the relationship with Trierweiler, for whom he left Segolene Royal, the mother of his four children, in 2005.
In a follow-up story, Closer depicted Hollande's romance with Gayet as more than a brief fling, saying it had possibly started "two years ago".
But it offered little in the way of concrete evidence and no pictures to back up its account.
Gayet is seeking damages of 50,000 euros ($67,000) from the magazine on the grounds that its first report was an illegal breach of her privacy. A trial date has been set for March 6.
Hollande has not denied the magazine's report and has ruled out any legal action on his own behalf.
Public reaction to the scandal has been more muted than would be expected in countries like the United States or Britain.
A poll by BVA for i-Tele released Saturday showed 75 percent of respondents agreed that Hollande was right not to answer questions on his personal life, and 62 percent believed the affair was a private matter of no public concern.