Her upcoming appearance in the new line-up was confirmed during an appearance on BBC Radio 1 Xtra, with Alex saying she’s “absolutely buzzing” to be taking part.
She said: “It’s the show I’ve always wanted to do and I can’t believe I’m finally going to be part of it.
“I’m super excited, but also terrified at the same time… The football pitch is a bit less glam than the ballroom, but I’m ready to try the sequins and dresses! Bring it on!”
Alex is the former captain of Arsenal and previously appeared in England’s national team, before going on to become a pundit and commentator, most notably during this year’s World Cup.
In 2016, it was announced that she was to receive an MBE for her services to football in the Queen’s New Year Honours List.
Alex also has some reality TV experience, having won the Bear Grylls show Mission Survive back in 2016.
Just three spots remain on this year’s line-up, with rower James Cracknell, Radio 1 DJ Devin Griffin, Atomic Kitten singer Natasha Hamilton and presenter Anneka Rice among those rumoured to be taking up the last slots.
Already confirmed are comedian Chris Ramsey, footballer David James, soap stars Catherine Tyldesley and Emma Barton, YouTube vlogger Saffron Barker, celebrity chef Viscountess Emma Weymouth and Paralympian Will Bayley.
Joining them will be RuPaul’s Drag Race judge Michelle Visage, Made In Chelsea cast member Jamie Laing, Mike Bushell of BBC Breakfast and CBBC presenter Karim Zeroual.
Strictly Come Dancing returns to BBC One in the autumn.