Declan Donnelly has announced the birth of his baby son with wife Ali Astall.
The BGT and I'm A Celeb host hailed his second child as a "welcome ray of light" following the death of his brother earlier this month.
He went on to say that his eldest daughter is "beyond excited to be a big sister".
The news will come as a huge surprise to most fans as the couple had not announced that they were expecting a second child.
Dec, 46, wrote on Twitter: "Shortly before 10am yesterday, 23.7.2022, Ali and I welcomed the arrival of our son, Jack Anthony Alphonsus, a very welcome ray of light. He is wonderful and Isla is beyond excited to be a big sister! D x."
Fans rushed to congratulate the presenter, with one tweeting: "NO WAY!!! did anyone know Ali was pregnant?!?!? My jaw is on the floor."
While another commented: "A huge congratulations to both you and Ali, Dec!"
A third wrote: "Congratulations Dec and Ali your children are going grow up like their parents. Dec I have a question What does it feel like being a farther I am so happy for you Dec. Please reply back Dec."
"Oh my goodness, these are the best news ever!! Huge congratulations to you and Ali, you deserve all the happiness in the world," another wrote.
Dec's celeb pals also congratulated the presenter, with Masked Singer host Joel Dommett commenting: "CONGRATS!!"
While Scarlett Moffatt wrote: "Congratulations. Delighted for you all love the moffatts xx"
Love Island's Laura Whitmore gushed: "Delighted for you both! Congrats."
The positive news comes just weeks after his brother, Father Dermott Donnelly, died at age 55.
Dec is said to have raced to his brother's side after he fell seriously ill.
Dermott, who officiated the TV star's wedding in 2015, is understood to have been rushed to University Hospital of North Durham with a suspected bleed on the brain after he collapsed.
Dec, 46, paid tribute to his beloved brother and said he was "beyond devastated" in a tweet.
It read: "I am heartbroken to tell you that my darling brother Fr Dermott, @TweeterPriest, sadly passed away this afternoon. We are all beyond devastated. Thank you for your messages of sympathy and support, they are appreciated."
Father Dermott was understood to have been a priest for 30 years.
Meanwhile, a spokesperson for Dec told the Mirror: "It is with great sadness that we confirm the death of Fr Dermott Donnelly who died peacefully this afternoon in hospital surrounded by his family and close friends."
Dec and Ali, who wed in 2015 in a lavish ceremony with Ant as his best man, welcomed their first child in 2018 - with the presenter gushing at the time that he was "head over heels".
He wrote at the time: "Ali and I are thrilled to announce the arrival of our baby girl, Isla Elizabeth Anne, who was born just after 9 o’clock this morning," Dec posted on the page he shares with Ant McPartlin.
"Mother and daughter both doing well, Dad is head over heels! D x."
Prior to welcoming his two children, Dec spoke frequently of his desire to have a family.
The presenter, who is one of seven children born to Irish Catholic parents, first began dating Ali in August 2013 and it is believed they started trying for a baby as soon as they wed two years later.
Back then, Dec said having children was “the next stage of our lives”. He added: “I’m looking forward to that.”
Asked last year if he would like children, he said: “Absolutely at some point, when the time is right.
"Hopefully, as Ant says, if it comes along, then it would be great.”
