But they reserve a special dislike for Juventus and it is a hatred that really took hold in 1982 where some dubious refereeing saw Juve snatch the Serie A title from the Purple Ones' grasp.
On the final day of the season, Fiorentina had a goal disallowed in their game against Cagliari, which finished 0-0 and helped Juventus, who beat Catanzaro 1-0 thanks to a Liam Brady penalty, win the league by a point.
That would anger any fan and a rivalry was born – better to be second than to be thieves, Fiorentina supporters thought. Not that they were bitter.
As John Foot explains in Calcio: A history of Italian football, you will see stickers around Florence reading zona anti gobbizzata – hunchback free zone.
Hunchbacks are said to bring luck in Italy and jammy Juventus have had more than their fair share in the eyes of Fiorentina fans.
Again, not bitter.
The 1990 UEFA Cup final where Juve beat Fiorentina only fanned the flames, but La Viola’s decision to sell golden boy Roberto Baggio, who joined the club at 18 in 1985, to the enemy for £8m shortly afterwards saw fans riot.
In the brilliantly insightful Calcio’s Greatest Forwards - a must for any footy nostalgia fan - author George Rinaldi reveals there were actually around three days of protests where more than 50 people were injured and club president, Ranieri Pontello, was forced to take refuge in the stadium.
And the spotlight was on Baggio in April 1991 when he returned to the city with Juventus in a Serie A match.
Him and his team-mates were not received warmly and police were clearly predicting more trouble given they felt the need to escort the club's bus through Florence and into Stadio Artemio Franchi.
Fiorentina won the game 1-0, but the flashpoint came when Juventus were awarded a penalty and Baggio refused to take it, later claiming to not be in the right frame of mind.
The visiting support were not pleased especially when Luigi De Agostini stepped up and missed the spot kick in his place.
However, the drama didn’t end there.
Baggio was later substituted, but managed to further enrage his new fans by picking up a Fiorentina scarf - thrown from the crowd - as he made his way around the pitch.
He eventually left Juventus in 1995 with a Ballon d’Or to his name and later played for Milan, Bologna, Inter and Brescia.
Think he missed a penalty somewhere, too, but that was so rare it probably wasn't anywhere important.