The 44-year-old star - who has children Brooklyn, 19, Romeo, 16, Cruz, 13, and Harper, seven, with her husband David Beckham - left much of her singing career behind when Spice Girls disbanded in 2000, and has since moved into fashion designing, setting up her own eponymously titled label in 2008.
"Bringing girl power and our message of friendship and love back to the stage feels more relevant than ever".
2 Become 1 was the Spice Girls' third single, and was the UK Christmas number one single in 1996.
In a video shared on the band's newly-created Twitter account, the 4 remaining members staged a mock news broadcast to confirm the tour, featuring them starting to sing one of their old songs.
The Spice Girls announced they will be going out on tour together on Monday, but Victoria Beckham aka Posh won't be joining her girls on stage.
Formed in 1994, the group racked up album sales in the tens of millions with hits including Wannabe and Say You'll Be There that topped charts across the globe.
Samsung Set to Reveal Actual Foldable Phone Details Tomorrow
According to a recent Bloomberg report, design of the foldable phone, codenamed victor , hasn't been yet finalised. Folded up it becomes closer to normal smartphone size, though it's still significantly wider than most phones.
Tickets will go on sale this Saturday.
The last time the group reunited was in 2012 for the closing ceremony of the London Olympics.
Sadly for Aussie fans, there are now only six shows scheduled - all in the UK.
The Spice Girls previously performed as a four-piece for two years after Horner quit the band in 1998.