The former Spice Girl will take to the sofa to cover Ruth and Eamonn's spot on Friday August 25th, with he ITV show taking to Twitter to confirm the news.
'We're ready to spice up your life this August Bank Holiday with @GeriHalliwell guest presenting on our famous sofa!' they wrote. 'Stay calm @Rylan!'
Rylan, who is now a regular presenter on the programme, will no doubt be delighted with the appointment, having declared himself to be a huge Spice Girls fan in the past.
Geri herself responded to the news when she retweeted the tweet by This Morning and used kissing emojis before saying: '@Rylan can't wait'
A source revealed to the MailOnline: 'Geri wants to reinvent herself as a telly host and this was an offer she couldn't turn down. On her studio visit last week she said she was "over the moon" to be joining the team.'
They added: 'She is very popular and has a massive following, especially with stay-at-home mums.'
Geri has been busy recently - in addition to becoming a mum for the second time back in January 2017, she's released a new record and has been taking on other presenting jobs.
Last week she filled in for Zoe Ball on her BBC Radio 2 show, and has also guest presented Loose Women.
Geri also released her first single in 10 years this month, Angels in Chains - which was a tribute to her friend George Michael, who passed away at the end of last year.
In addition to her professional pursuits, Geri shares frequent social media updates to give fans insights into her family life with daughter Bluebell, 11, son Monty, six months, and husband Christian, who is Team Principal of the Red Bull Racing Formula One team.