The men were seized by US forces in Afghanistan on suspicion of fighting with the fallen Taliban government there.
Relations have been frosty between Paris and Washington since they fell out over the US-led invasion of Iraq. They remain divided in global trade talks and have clashed over whether Turkey should become a member of the European Union.
A French Foreign Ministry spokeswoman had earlier declined to name the men released or give details of their arrival in France.
Jacques Debray, a lawyer for one of them, said the ministry had told him that France chartered a plane to bring the men back.
"They will very likely be placed in detention ... . In terrorism cases detention can last up to four days," Debray said.
The US previously released some
prisoners to Britain and Denmark
The men will be interrogated by a top "anti-terrorist" magistrate and could be put under formal investigation, which under French law is the final stage before charges can be made, he said. It was too early to say what they might be charged with.
Among those detained at Guantanamo was Mourad Benchellali, son of an imam from Lyon. The imam is under investigation by "anti-terrorist" magistrates along with his wife, another son and three others.
The French nationals were among about 600 suspects still held at Guantanamo after being captured during the US-led war in Afghanistan, after the September 11 attacks.
"They will very likely
be placed in detention.
In terrorism cases detention can last
up to four days"
lawyer for one of the freed French Guantanamo inmates
Washington, criticised by human-rights groups and many governments for holding the detainees without charging them, has already handed over some prisoners to Britain and Denmark.
The US Supreme Court in June ruled that the Guantanamo inmates could challenge their detention in US courts, a decision seen as a major setback for the Bush administration.