"Private affairs are dealt with in private," he said in his Jan. 14 news conference as he ducked questions from journalists about his personal life.
The separation will leave the president living as a single man, and France will no longer have a de facto first lady. Although there is no official title of first lady in France, Trierweiler had accompanied Hollande at official functions and traveled with him on state visits. Their relationship began in 2005.
Trierweiler, a journalist, will return to private life, but it was not clear whether she would go back to journalism.
The announcement came, as Hollande had promised it would, ahead of an official trip to Washington, planned for Feb. 10, during which he will spend time with President Barack Obama, be honored at a state dinner and then go on to San Francisco to meet with business leaders.
The magazine, Closer, published photographs of Hollande visiting an apartment building where the actress, Julie Gayet, 41, lived, and it revealed to the public details of the president's private life, which were already circulating among French journalists and close associates. One photograph showed the president, his face obscured by a motorcycle helmet, on a motor scooter at the Paris apartment building. Another showed him walking out of the building.
When Trierweiler saw the magazine's photographs, she had an "emotional collapse," according to her staff, and was hospitalized for more than a week. Since her release from the hospital last Saturday, she has been staying at a presidential residence outside Paris.
She and Hollande did not live in the presidential palace but in Trierweiler's Left Bank apartment, and it was not yet clear where each would live now. However, the French news media was reporting that Trierweiler would return to her apartment and Hollande would live for the time being in the presidential palace.
Hollande's announcement came as Trierweiler was preparing to leave for India on behalf of a charity with which she had been active.
Neither Hollande nor Trierweiler has spoken to the media on the record, so neither of their versions of the breakup is public. It seems likely that at least one of them will speak about it in the future.
Also unclear is Hollande's relationship with Gayet.