The London trio hopped out of a private helicopter to let fans know, in a video posted on social media.
Dappy and Tulisas fathers are Cypriots.
They made the announcement (Monday 16 May), 11 years after the group first announced a two-year hiatus.
Dappy, Fazer and Tulisa released their new song Charmer, and got its first play on Radio 1Xtra.
The video, which all three members posted on their Instagram accounts, includes a very brief snippet of new music.
Aitch, Unknown T and Yungen were among the big names to react in excitement at the announcement.
The live shows will start on 7 November and are booked in some of the biggest venues in the UK – including London’s O2.
They separated to pursue solo careers – to varying degrees of success.
Tulisa scored a solo Number One single in 2012 with her debut release, Young, and followed it with two more Top 20 hits – but releases since then have failed to chart.
Dappy also had a run of solo success – scoring two Top Ten hits (No Regrets and Rockstar) from his debut album Bad Intentions.
More recently, he’s charted with tracks such as Oh My and Motorola.
Fazer has also released solo music, including a collaboration with Tom Parker from The Wanted.