The duo joined their Atlanta, Georgia hip-hop collective cohorts Goodie Mob, Sleepy Brown, and Killer Mike to headline the One MusicFest at at Aarons Amphitheater in Lakewood, Georgia.
Past tensions between the old friends were put aside for the gig and the audience went wild when the collective's most successful member Andre 3000 made an unannounced appearance during Goodie Mob's Black Ice (Sky High), and later reteamed with Big Boi to perform Outkast hits Hootie Hoo and So Fresh, So Clean.
Another highlight came when Andre 3000's ex-girlfriend Erykah Badu joined him for a rendition of Liberation, and Goodie Mob's Cee Lo Green also thrilled the crowd with a rendition of his Gnarls Barkley hit Crazy.
The get together marked the first time Big Boi and Andre 3000 had performed on stage together since they hit the road in 2014 for a festival tour.
News of a reunion of sorts leaked last week (ends11Sep16) when rapper Gucci Mane revealed he had been working on new music with Outkast in a video posted online.
Representatives for the rap/funk duo quickly shot down the reports, stating, "There is no Outkast news to report".
The duo has not released a studio album since 2003's Speakerboxxx/The Love Below.