Hannah Spearritt, Paul Cattermole, Jon Lee, Bradley McIntosh, Rachel Stevens, Tina Barrett and Jo O'Meara will be hitting the road next month on an arena tour.
Sharing a rehearsal photo via Twitter last night, they said: "#BRINGITALLBACK2015 rehearsals are off and running. Is everyone excited? Because we are! #sclub7."
S Club 7 first reunited in November last year to perform a special medley for Children In Need.
Speaking of their reunion, Hannah said last month: "It's taken a while for us because getting seven diaries together has been quite a feat.
"And also I think we've wanted to wait a while as well because now it's quite cool and vintage because it was so long ago. It's lovely to come back."
The pop group originally formed in 1998 and rose to fame after starring in their own BBC television series, Miami 7. They achieved four number one hits with songs including 'Reach' and 'Bring It All Back'.
S Club 7 split in 2003 following Paul's exit from the band in 2002, but they returned after a 12-year hiatus.
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