The couple married in 2000, and share five children together, Poppy, 19, Daisy, 18, Petal, 12, Buddy, ten, and River, four.
And the pair's relationship is clearly still going strong as to mark Jamie's birthday, Jools shared a romantic photo of the couple alongside a heartfelt tribute to her husband.
WATCH: Jools Oliver declares her love for Jamie in hilarious interaction
In the black-and-white photo, the twosome looked smitten with each other as they smiled in a photobooth.
"My absolute big legend number 1," she lovingly wrote. "Happy birthday my beautiful soul mate and best friend, so glad we get to spend it together."
She ended the post with a string of emojis including an anchor, boat and sunshine.
Many fans rushed to wish the celebrity chef a happy birthday, while others were bowled over by Jools' emotional words.
"You guys," enthused several, while another added: "Aw, you 2 love birds," and a third posted: "You two! Excellent combo – beautiful children."
Jools posted a heartfelt message for Jamie
Jools also shared another romantic snap from the pair's day on her Instagram Stories, which saw Jamie taking a small nap while the sun beautifully set in the sky.
"Night night birthday boy," she captioned the image.
The couple married in 2000
Jamie recently revealed on Fraser T. Smith's podcast, 12 Questions, that his wife, along with their three daughters and some of his female colleagues, help him stay "grounded".
"I think we all have to control our egos," he said. "I mean, my best way of controlling my ego was just to work with lots of women, to be honest. And I think they keep me in line.
"Like, for the last 20 years, we've been about 80% ladies in the business, and somehow it's just worked very well for me.
"And they don't sit there telling me how great I am all day, let's just put it that way. They keep me in check, as well as my wife. And now my daughters."
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