The heaviest sentence was reserved for Karim Mohamed-Aggad, the brother of the Bataclan suicide bomber Foued Mohamed-Aggad , who was sentenced to nine years in jail. All seven men will be placed on a register of terrorists.
Foued Mohamed-Aggad travelled with the same group to Syria but did not return home with them.
Nearly two years later he blew himself up at the Bataclan concert venue in Paris where 90 people were murdered.
The lawyer for Karim Mohamed-Aggad, Me Françoise Cotta, said that her clients will appeal the sentence.
The defendants, all friends from the eastern city of Strasbourg, and all deny having fought as jihadists while they were there.
They claimed their trip was meant to be dedicated to humanitarian aid work, but that they got caught in jihadi crosshairs and were forced to join "Islamic State.
Controversially, prosecutors used as evidence in the trial a trove of alleged IS group documents leaked to British TV station Sky News in March, in which thousands of individuals with links to the terrorist organization are listed.
The move has been criticized by the defense lawyers.
The documents contain some 22,000 names of individuals linked to the IS group in 2013 and early 2014, the investigation source said.
An estimated 173 of those names are French citizens or residents of France, including several who have died in Syria and Iraq and two more of the Paris attackers – Samy Amimour and Omar Ismail Mostefai.
The documents, written in Arabic under the title "General Border Administration", log the name, blood type, date of birth, previous job, level of religious education and more of each new arrival to the IS group zone of control.
They are also listed as "combatant", "martyr" or "Inghimasi", a term referring to fighters who carry weapons as well as an explosive suicide vest.
The documents listed the seven men from Strasbourg as "combatants".