The six defendants were convicted of "violence with arms", with aggravating circumstances such as premeditation.
Clermont hooker Benjamin Kayser and centre and skipper Aurelien Rougerie suffered arm injuries while lock forward Julien Pierre was the most seriously hurt with deep slashes to his hips in the "brutal" attack in the early hours of July 20, 2014.
A court in Rodez, northeast of Toulouse in southern France, heard how the three players were set upon by around a dozen men, some riding scooters, and wielding knives, machetes and swords in the terrifying assault outside the nightspot in Millau.
The six defendants, all residents of Millau, were convicted of "violence with arms", with aggravating circumstances such as premeditation.
The Clermont squad was staying in the town for a pre-season training camp.
The court heard that the attack followed a verbal altercation outside the club, provoked by Rougerie reportedly confronting a man who had "insulted a woman" inside the building.
Jean-Marc Lhermet, the Clermont sporting director at the time of the incident, told AFP the attack was "as unexpected as it was brutal".
Rougerie, a former captain of the French national team, has spent all of his career at Clermont, making more than 350 appearances as well as winning 76 caps.
Kayser has 37 caps for the national side while Pierre, a Clermont player since 2008, has made 27 appearances for France. Pierre needed surgery after the attack.