The Big Brother turned This Morning presenter, 45, gushed over how "innocent" she was back then.
Taking to social media, she shared the snap with her some 687,000 Instagram followers.
Wearing an oversized blue coat, white knee socks and a giant red ribbon bow - Alison looks absolutely precious.
She addressed her followers with: "This is me age 3! How cute was I. So innocent and with my whole future ahead of me.
"It's just so lovely"
"My oversized coat and red ribbon it’s just so lovely. Thought I would share."
Fellow presenter Lisa Snowdon replied with a series of heart emojis.
And Loose Women star Saira Kahn posted: "Beautiful - just like now x."
Another user quipped: "Standard parent buying...'she’ll grow into that' I don’t think anything I had as a child fitted for the first few months. Still cute tho."
A further user commented: "You are literally adorable! x."
Her trip down memory lane comes just as it has been reported that she is set for a bigger role on This Morning.
Alison Hammond presenting This Morning
Alison has been a guest presenter on the ITV magazine show from years.
She's fronted everything from celebrity interviews to competitions to travel segments.
And now she, along with Dermot O'Leary, are set to step into Phillip Schofield and Holly Willoughby's shoes.
The pair will take over as hosts this summer on the morning chat show.
Alison and Rochelle Humes will co-host on the last Friday of July and the first of August.
And then Alison will continue to co-host this day with Dermot for the rest of the month.
Monday to Thursday will be covered by Eamonn Holmes and Ruth Langsford.
This Morning's Editor Martin Frizell said: "We’ve been inundated with viewers’ positive feedback throughout lockdown on how This Morning has provided that much needed comfort blanket each day.
"As the nation eases itself out of lockdown over the summer, we promise to continue to bring viewers more of what they trust us to do best - reflecting their real lives at home and what matters to them most."
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