On Instagram, the 24-year-old shared three photographs of her newborn son, whose name has not yet been revealed.
In the first image, Dyer is pictured kissing her baby’s head at The Portland Hospital in London.
In the second, the baby boy is pictured sleeping alone and in the third, Dyer’s boyfriend, Sammy Kimmence, is photographed kissing him.
In the accompanying caption, Dyer expressed her gratitude for her newborn son, who was born on 23 January.
“After a very long day and night finally our special little boy arrived 23/01/2021,” she wrote. "Weighing 7 pound..We are in a complete baby bubble and enjoying every moment, can not believe he is ours, completely in love and so grateful to be his mummy."
The former Love Island star added: “The best experience ever will never forget this day.”
Dyer’s post has already garnered more than 800,000 likes and thousands of comments from fans and fellow celebrities.
The cleaning influencer Mrs Hinch commented: “Awwww. Amazing amazing news , congratulations beautiful!! Sending lots of love and hugs.”
Fellow former Love Island star Georgie Steele added: “ love him so much already”.
Kimmence, a stockbroker and footballer, also posted about his newborn son on Instagram, writing: “Wow I just simply cannot put this moment into words, a day I will never forget with a boy I will never stop loving. You have my heart son and wow what a woman your mother is.
“To say I'm grateful is an understatement. Can't wait to start my perfect little family with you baby Kimmence due 2021.....time to hang my boots up from vine FC.”
Dyer announced that she was expecting her first child with Kimmence in July. The couple dated prior to her appearance on Love Island in 2018 and rekindled their romance after Dyer broke up with Jack Fincham, whom she met on Love Island.