The Im A Celebrity and Britain's Got Talent host, Dec announced the birth of his and his wife's baby on social media.
The announcement of the newborn baby was made on Twitter on Saturday morning by Dec.
Dec said in his tweet, "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 also added that he is "head over heels!"
The pair, Declan Donnelly and his wife, Ali Alsall got married on 1st August in 2015. Ali is a talent manager, born in Newcastle, which is also the hometown of Dec.
The announcement of the birth and the expectation of their first baby was announced in early 2018, in March.
Declan's best friend, and other half of duo Ant and Dec, Ant McPartlin also gave his congratulations on Twitter over the birth of Dec's first child. Ant added, "Welcome to the world baby Isla Elizabeth Anne. Can't wait for cuddles. I love you already!!" signing the tweet off with "Uncle Ant"
Fans of Dec have also took to Twitter to express their congratulations to the pair.
One account, named Vintage AntandDec, said, "Congratulations to Dec @antanddec and Ali on the birth of baby Isla Elizabeth Anne. Now, I know that everyone is happy, but Shhh! You'll wake the baby!!!!!"
Another account, named @swearit, said in a Tweet, "@antanddec dec congratulations on birth of beautiful baby"