Playing in front of an expectant home crowd, Allegri’s players needed just a point to secure the title but went one better after Alex Sandro’s strike was doubled thanks to an own goal by German Pezzella in the second half.
Having lost to minnows SPAL last time out, missing the chance to secure their latest league title, nerves kicked in early in Turin when Nikola Milenkovic scored the opening goal after six minutes.
By claiming the Scudetto, Ronaldo became the first player in history to win Serie A, La Liga and the Premier League.
It is a record as the Old Lady’s dominance sees them become the first side to go eight titles undefeated in Europe’s top five leagues.
The disappointment of their European exit to Ajax at this ground back on Tuesday evening was, for 90 minutes at least, quickly forgotten as players, staff and supporters celebrated a piece of history.
Victory over Fiorentina represented Juventus’ 28th win from 33 Serie A games this season which sees them with 87 points, 20 more than Napoli in second.
Allegri was mobbed at the final whistle with Colombian winger Juan Cuadrado, replaced by Mattia de Sciglio with three minutes remaining, covering his manager in canned foam.
Moments after the final whistle was blown, Juventus posted a video to their YouTube channel as a trailer for a full-length film that will re-run the record-breaking season.
Social media soon became awash with reaction of the title win as club captain Giorgio Chiellini posted a collage photo of himself celebrating each of the eight titles in this record won, captioned #w8nderful.
After the disappointment of their exit in the Champions League, a lot of the immediate focus was on the future of Ronaldo but he quickly dismissed suggestions he is looking for a move away after one season.
The five-time Ballon d’Or winner told DAZN: ‘My future? I will be at Juventus next year 1000 per cent, I’m very happy for the Scudetto & the Super Cup.
‘We have behaved well in the Champions League, next year it will be better.’
There were title celebrations earlier in the day for Juventus as the women’s team, including England’s Eniola Aluko, wrapped up their domestic title with victory over Verona.
Aluko got herself a goal as Juventus women ran out 3-0 winners on the day after earlier strikes from Petronella Ekroth and Cristiana Grielli ensured the whole club swept the board with titles.