Guitarist John Squire, frontman Ian Brown, drummer Alan 'Reni' Wren and bassist Gary 'Mani' Mounfield made the announcement at the Soho Hotel.
The band will play a pair of dates at Manchester's Heaton Park on June 29 and 30 before embarking on a world tour. They also confirmed plans to record new material, their first since 'Ten Storey Love Song' B-sides 'Moses' and 'Ride On' in 1995.
Tickets for the reunion shows will go on sale this Friday, October 21 at 9.30am.
Asked about the possibility of releasing a new album, Brown said: "We hope so. But we said that before, didn't we?"
On what had changed since his past claims that a reunion would never happen, Squire said: "Everything changed when me and Ian started seeing each other again.
"It was surreal, we went from crying, laughing about the old days, to writing songs in a heartbeat."
Brown added: "This is a live resurrection that we're inviting you to, so you'd better be there."
He denied suggestions that the reunion was all about the money and explained to Digital Spy: "The money's always been on the table. We could have took that money any time we wanted."
> Read what The Stone Roses had to say at today's press conference
The Stone Roses had repeatedly denied previous rumours of a possible comeback that had surfaced in recent years.
Despite Mani suggesting that enough money could secure a return, Squire maintained that it would never happen and Brown agreed.
Squire made a metal artwork in March 2009 called Statement which featured the text: "I have no desire whatsoever to desecrate the grave of seminal Manchester pop group The Stone Roses. 18-3-09."
Brown and Squire originally formed the band in Manchester 1983, with Reni joining a year later and Mani playing his first show in 1987.
The Stone Roses signed to Zomba's Silvertone Records subsidiary in 1988 and released their self-titled debut the following year.
Standalone singles 'Fools Gold' and 'One Love' followed, before a falling-out with Zomba.
The band then signed with Geffen and began work on the follow-up, but legal difficulties caused delays. Second Coming, mainly penned by Squire, was released in December 1994.
Reni left the band in March 1995 and was replaced by Robbie Maddox. Squire then quit in April 1996, with Aziz Ibrahim taking his place for a further six months of live shows, including a poorly-received concert at the Reading Festival.
Following the band's split, Squire went on to form The Seahorses who released one album Do It Yourself. He then recorded two solo albums Time Changes Everything and Marshall's House before retiring from music to focus on visual arts.
Mani joined Primal Scream in 1996 and has remained with the band until today. Reni has reportedly fronted several bands without commercial success.
Brown has released six solo studio albums since his debut Unfinished Monkey Business in 1998.
> The Stone Roses to release new biography
> The Stone Roses: What have they done since the split?
> Stone Roses reunion: Should they? Shouldn't they? - Poll
Watch The Stone Roses 'I Am The Resurrection' live music video below:
Move through our images from The Stone Roses' career below: