The Essex-born farmer, who has appeared alongside childhood friend Jamie Oliver on many BBC and Channel 4 programs, is now a dad to three girls after welcoming a baby girl with wife Michaela Furney.
Jimmy has been married to Michaela for six years, and already has two daughters Cora Mae and Molly Rose.
Clearly overjoyed by the news and unable to keep it from his fans, Jimmy announced the news to his 58.6k Instagram followers only two hours after the birth.
He posted a photo to the social media website with the caption; 'Best Christmas present ever! Only 2 hrs old another little girl to join the family. Both baby and @caeladoherty doing well.'
However, he has not yet revealed the name of his new tot. Even when posting a second photograph the day after, captioned; 'Day two for my new little girl.'
The 40 year old tied the knot with his long-term partner at their farm in Suffolk on 22nd August 2009, which was famously detailed in their many TV shows.
Jamie will be able to give his old friend some tips on raising daughters, as he also has three of his own with wife Jools Oliver - Daisy Boo, Petal Blossom and Poppy Honey - as well as son Buddy Bear.
The new dad became friends with TV chef and dad Jamie Oliver when they attended Newport Free Grammar school together.
Jimmy shot to fame on documentary Jimmy's Farm, which followed him rearing pigs, living the 'good life' after leaving London and his battle to establish himself in the industry.
He most recently collaborated with Jamie on his recent venture Jamie and Jimmy's Friday Night Feast, which showed the pair meeting celebrities at Jamie's restaurants and challenging them to cooking competitions.