ENTRY/EXIT REQUIREMENTS: France is party to the Schengen agreement. As such, U.S. citizens may enter France for up to 90 days for tourist or business purposes without a visa.
A passport is required and should be valid for at least three months beyond the period of stay. Anyone intending to stay more than 90 days must obtain the appropriate visa issued by one of the French Consulates in the U.S., prior to departure for France. This also applies to anyone considering marriage in France.
http://travel.state.gov/travel/cis_p...y_requirements