Ribery, who was substituted with 15 minutes remaining in the game, twice shoved the official on the pitch following the Viola's 2-1 defeat.
The league found the Frenchman to have "come forward with a threatening attitude and disrespectful behaviour towards an assistant, in addition to disrespectful words".
Ribery was angry that Ciro Immobile's winner for Lazio was allowed to stand, with Fiorentina adamant a foul had taken place in the build-up.
The ban means he will miss games against Sassuolo, Parma and Cagliari.
Earlier on Monday he took to social media to issue an apology to the official and everyone associated with Fiorentina.
"I'm really sorry for last night," a post on Twitter read. "I apologise to my team-mates, the coach and the fans. I also apologise to Mr [Matteo] Passeri because at the end of the match I was very agitated and sad, and I hope he can understand my mood.
"I always want to stay on the pitch and help my team-mates because I came all the way to Florence for this city and this club, and I think Fiorentina should get more attention, the same attention given to other clubs, for the great work we're doing every day."