The presenter welcomed her little boy just three weeks after going on maternity leave, but couldn't resist calling in to make the very exciting announcement herself.
However, as well as informing hosts Matt Baker and Angela Scanlon of the new arrival, she also called on BBC One viewers to help come up with a name for the newborn.
"Hello and welcome to The One Show with Matt Baker," Angela, 33, had opened with, while her companion added excitedly: "Angela Scanlon and… Alex Jones is on the phone, right now."
Matt, 39, continued: "Hang on, hang on, hang on, why on earth are you ringing? Do you have some news?"
The One Show: Alex Jones has welcomed a baby boy
The One Show: Alex Jones announced the news live on the BBC show
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We're absolutely delighted and completely in love with him.
Alex, also 39, went on: "Well I do have some news. Our beautiful, healthy little baby boy has been born.
"We're absolutely delighted and completely in love with him. It is the most wonderful feeling."
When asked for more details, the brunette beauty said: "He was 7lbs 11 – a lovely weight – it was all very straightforward and lovely actually.
"Charlie [Thomson, her husband] was with me, mum and dad were in the waiting room. We didn't know if it was a boy or a girl. The last four days have been heaven, we have been in this bubble the three of us, it's just the best time."
The One Show: Alex Jones with her husband Charlie
The One Show: Matt Baker and Angela Scanlon congratulated her live
However her next request was rather an unusual one: "We're a bit behind on the whole name thing, because we didn't know if he'd be a boy or a girl. We thought when we see him we'll know what he looks like.
"So, maybe some help? Everything we ask of them [viewers], they come up with the goods…"
Matt the stepped in and suggested those at home send in photos of their new arrivals and their chose names.
The One Show airs weekdays at 7pm on BBC One.