The boyband will celebrate their 20th anniversary with a number of shows later this year.
Ronan Keating welcomed bandmate Shane Lynch on stage at his solo gig at London's O2 Arena on Saturday night (January 26).
The tickets for the new tour will go on sale on Valentine's Day (February 14), with full dates and venues expected to be announced soon.
Lynch told the crowd: "Ladies, it's the time of year you usually get flowers and chocolates. But now you can also get Boyzone tickets."
Boyzone with Stephen Gately in 1997
Boyzone previously toured the UK and Ireland to support their latest album Brother.
It was the group's first tour since the death of former bandmate Stephen Gately in 2009.
Shane Lynch recently warned One Direction, telling them not to get "sucked into the world of drugs".
Watch the video for Boyzone's 'Gave It All Away' below: