After facing 60 years in jail, Florence Cassez, 38, left Mexico City's Tepepan prison around four hours after three of five justices voted for her immediate release in a case that had strained Franco-Mexican ties.
She headed to the airport to fly to Paris yesterday night with her father Bernard, seven years after she was jailed on kidnapping charges.
"It is a historic day for Mexican justice," her French attorney, Frank Berton, told reporters.
Cassez's case has put a spotlight on Mexico's troubled justice system, where most crimes go unsolved and authorities are often accused of corruption and abuse.
But her release angered victims rights activists. Some people shouted "murderer!" as Cassez was driven away from prison.
Cassez, who has always proclaimed her innocence, was accused of being involved with a gang of kidnappers known as the Zodiacs, allegedly run by her ex-boyfriend Israel Vallarta.
But the Supreme Court justices ruled that the police violated her rights by staging her arrest in a live national television broadcast on December 9, 2005.
Mexican television showed police storming Vallarta's ranch near Mexico City on December 9, 2005, where they detained Cassez and freed three hostages as cameras rolled.
Interviewed on the spot by Televisa, the slight, red-haired woman looked stunned as she said: "I have nothing to do with this. I'm not his wife. I didn't know anything!"
It was later revealed that Cassez had actually been arrested on a road hours before the raid. The federal police said the re-enactment was made at the request of the media.
Though all five Supreme Court justices agreed that Cassez's constitutional and human rights were violated, two of them said the case should be sent back to lower courts.
Voting for her immediate release, Justice Arturo Zaldivar Lelo de Larrea said "those responsible for the violation of Florence Cassez's human rights are the authorities."
The court found that the authorities violated her right to presumption of innocence and immediate access to consular support.
The Supreme Court already examined her case last year, but the panel was split on whether to release her, even though four of the five justices then agreed that there were irregularities in the case.