Radio France Internationale said Guillaume, a 37-year-old artist, and Patrick, a 48-year-old photo lab manager, married in the southwest France town of Cabestany.
In their marriage vows, they said, "Unfortunately, this document has no official character, since the law today forbids marriage between people of the same sex, but it signifies the wish of the local authority to see the law change."
The town's mayor, who presided over the wedding, called on other mayors to follow his example.
"There are times when you have to be an outlaw," Mayor Jean Vila said before Saturday morning's ceremony.
French Families Minister Claude Greff criticized the ceremony as an "electoralist provocation" in advance of the 2012 presidential elections and said it would make positions on same-sex marriage more inflexible.