It is the Turin giants’ 30th official title in Italy’s top flight and third in succession under coach Antonio Conte.
Juventus remain on course to become the first team in Serie A to finish with at least 100 points.
After hosting Atalanta on Monday, Juve travel to Roma next week and close out the season at home to Cagliari.
Juventus had congregated at a hotel in Turin on Sunday afternoon to watch Roma’s upset on television and immediately after the final whistle the celebrations began.
Several players, among them striker Pablo Daniel Osvaldo, posted brief messages on Twitter: “Campioni !!!!”
“We are the champions, we are the champions,” read another from the club’s official Twitter feed alongside pictures of the players dressed in identical black t-shirts making reference to the club’s belief they have won 32 titles.
Juventus were stripped of two Serie A titles, which they won in 2005 and 2006, following their demotion to Serie B for their role in the Calciopoli match-fixing scandal.
Defender Leonardo Bonucci made reference when he posted a message on Twitter which read: “Champions 32.”
“I’m very happy, we’ve won the title and I’m really happy for everyone at the club,” Juve striker Carlos Tevez told reporters.
Roma had emerged as Juve’s only real challengers this season after setting a new Serie A record of 10 opening wins under French coach Rudi Garcia.
But despite the capital club clinging to Juve’s heels in recent weeks and Garcia remaining defiant, the Roma boss on Saturday finally conceded defeat to Juventus.
“The championship is over. Tomorrow’s (Sunday’s) result at Catania won’t change a thing, but we’ll still be going there looking to win,” said Garcia.
After a testing season trying to keep pace with the Juve juggernaut, which went on a 22-match unbeaten run following a shock 4-2 away defeat to Fiorentina in their eighth match of the season, Garcia’s words appeared to have a soporific effect.
Roma, expected to claim another 10th successive win to match their positive start to the campaign, were 2-0 down inside 34 minutes thanks to a brace from Mariano Izco and despite Francesco Totti reducing the arrears three minutes later the visitors were humiliated in a one-sided second half.
Roma, who still hold the record for the biggest winning margin in Serie A — following a 7-0 rout of Catania in November 2006 — went 3-1 down in the 55th minute when Gonzalo Bergessio pounced on the rebound from Sebastian Leto’s shot to beat Morgan De Sanctis in the Roma net.
Pablo Barrientos sealed the points and Juve’s early title celebrations when he sent an angled strike beyond the outstretched De Sanctis on 79 minutes.
Elsewhere, Torino and Parma boosted their hopes of European football next season with 1-0 and 2-0 wins over Chievo and Sampdoria respectively.
Torino’s win in Verona kept them in sixth place, the last possible spot offering a Europa League place via the Italian Cup.
Napoli, who are virtually qualified for the Champions League, won the Cup on Saturday with a 3-1 victory over Fiorentina, who are already virtually assured of a place in the Europa League.
Torino hold a one-point lead over Parma, who moved up to seventh thanks to goals from Antonio Cassano and Ezequiel Schelotto away to Samp, and a three-point cushion on Lazio and Verona, who face each other on Monday.
Milan are a point further adrift in 10th place but will be back in Europa League contention if they prevail over Inter in the city derby later Sunday.
Meanwhile, veteran Udinese striker Antonio Di Natale hit a brace in a 5-3 home win over Livorno, who dropped to bottom spot with Catania moving the other way.
Livorno have 25 points, one, three and four points fewer, respectively, than fellow-relegation candidates Catania, Sassuolo and Bologna.