The presenter hosted the show – which featured plenty of birthday surprises – sporting the same blue floral print dress her mum had worn on her own milestone birthday.
Revealing the significance of her outfit to co-host Phillip Schofield, Holly said: “I knew it would feel nice to wear something she had worn on her day, when it was the same day.
“But there was a bit of a moment this morning as I was zipping it up.”
She continued: “I was thinking, ‘This is quite weird. My mum did this on her 40th birthday and now I am doing it on my 40th birthday’. It was quite special.
“And it seems more special because I can’t be with her today, obviously. It is nice to have this and feel a little closer.”
Holly added: “I can’t be with my mum or dad today but wearing this in her honour makes me feel closer to them… love you Mumma!”
She also shared a throwback picture of Linda wearing the dress years earlier on Instagram.
“I remember this day so clearly. It’s a strange thing to reach the age you remember your Mum being!” Holly wrote.
Holly became tearful as she was surprised by Phillip and the This Morning team upon her arrival at the show’s studios on Wednesday.
The group clapped and sung Stevie Wonder’s Happy Birthday, with her dressing room adored with balloons, champagne and decorations.
In the studio, indoor pyrotechnics were hidden behind the ITV show’s sofa, and there was also socially-distanced party featuring a fake beach, a cocktail bar and Gok Wan as DJ.
Many of Holly’s famous friends have also been busy posting tributes to mark her milestone birthday online, including former Celebrity Juice co-star Fearne Cotton, who shared some photos of their times together in their 20s.
This Morning airs weekdays at 10am on ITV.