Even better, it was part of a tribute to his wife, Jools.
The celebrity chef took to Instagram, where he shared a photo of River standing in a field of daffodils.
The little boy smiled and held his hands over his head as he looked at the camera.
The four-year-old wore a very colourful outfit, made up of blue tracksuit bottoms and a co-ordinating blue, white, yellow and red top, which he teamed with rainbow-striped wellies.
Jamie captioned the snapshot: "Loving [rainbow emoji] trackie designed by @joolsoliver," finishing with heart and thumbs up emojis.
WATCH: Jamie Oliver reveals parenting struggle with 'phenomenal' son River
Jools launched her own fashion range for children in 2012 called Little Bird and the talented designer has teamed with Next to launch her latest collection.
The mum-of-five spoke exclusively to HELLO! about the range, sharing the role her kids play in her design process.
River looked so happy in his dad's sweet snapshot
"My children totally inspire me in everything I do," she said. "They all absolutely love clothes, and they think it's really cool that I have my own collection!"
Noting her daughters' retro sense of style, Jools added: "It's funny to see how my older girls are definitely influenced by past decades in fashion, especially the 80s, so they dress just like I used to at their age."
Jools and Jamie have been married since 2000 and share daughters Poppy, 19, Daisy, 17, and Petal, 11, as well as sons Buddy, nine, and little River.
Jamie recently shared a bedtime photo with his youngest son
The proud parents both like to share snaps of their children on Instagram, and earlier this week, Jamie posted the sweetest picture of his youngest son River as he read to him at night.
The pair looked up at the camera and smiled as the celebrity chef held onto a copy of the book Thud! Crash!.
"Bedtime stories with my bestie [heart emoji]," the Jamie's Keep Cooking and Carry On star captioned the lovely selfie.
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