Phil explained that Holly's three children were returning to school so she had taken the day off.
The presenter is mum to son Harry, 11, daughter Belle, nine, and son Chester, five.
Holly posted a snap to Instagram as she did the school run.
The picture showed Holly and two of her children's feet.
This Morning isn't the same without you but mum duties come first.
The star wrote: "The new norm... back to school..." followed by a red apple emoji.
Fans told Holly they were missing her on the programme.
One said: "Missing you this morning Holly."
Another wrote: "This Morning isn't the same without you but mum duties come first."
A third added: "Davina's doing very well with Phil, Holly but hope you're back on This Morning tomorrow."
Another commented: "Hope everything goes well @hollywilloughby with kids at school and can’t wait to see you back on This Morning missing you."
Holly takes a day off
At the start of today's show, Phil told viewers: "Welcome to a new week on This Morning," as he looked at Davina.
Davina said: "Hi, I’m here! Holly’s doing something lovely today."
Phil explained: "Holly is taking her children to school today, they're all going back.
"It's a staggered affair so it's quite complicated. I can imagine, quite high emotion so yeah she’s taking her kids to school as she should."
Davina admitted: "I’m very nervous but I'll just follow you, you’ve done it before so it’s okay."
Viewers were thrilled to have Davina on the show.
What did they say?
One person said: "Aw lovely to see Davina McCall on #ThisMorning."
Another gushed: "So nice to see Davina hosting with @Schofe on @thismorning! What a perfect fit for her, absolutely adore @ThisisDavina."
Another wrote: "Awww davina on #thismorning Holly’s with her kids."
However, others weren't impressed and wanted Holly back.
A fourth tweeted: "What! Where's Holly? I can't watch Davina, she's more annoying than Amanda Holden."
One added: "Where’s Holly?!"
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