Deeley who is married to Late Late Show host Patrick Kielty will step in to present the show alongside Rylan Clark next Monday and Tuesday, before co-presenting the show with Craig Doyle on Wednesday.
Thursday's show will be hosted by Craig Doyle and Alison Hammond, with Friday's show being co-hosted by Dermot O'Leary and Alison Hammond.
This comes as ITV look to replace former presenter Holly Willoughby, who stepped down last month, after a man was charged with setting a plot to kidnap and murder her.
"I have let ITV know today that after 14 years, I will not be returning to This Morning", Willoughby had said in a statement, having co-hosted the show for 14 years.
"To everyone who has ever worked on the show over the years, thank you so so much", she added. "This is such a difficult goodbye, you are incredible and I forever will be proud of what we've done together".
Back in May, co host Philip Schofield had left the show, after admitting to having a relationship with a younger male former colleague.
Last month, ITV confirmed that they had updated their policy regarding work relationships in light of the Philip Schofield scandal.
Employees at the broadcaster have been reportedly informed that they may face disciplinary action, and possible termination of employment, should they fail to declare a relationship.
