Dyer, 23, who is in a relationship with stockbroker Sammy Kimmence, shared a post on Instagram to reveal the couple’s news.
The first picture shows the couple sitting on a sofa together, Dyer holding a copy of her ultrasound scan, while the second picture shows a close-up of the sonogram.
“Little bubba can’t believe you are going to be ours,” the former Love Island winner wrote in the caption.
“Me and Sammy are so excited to start this next chapter in our lives, feel so lucky and grateful.. 2021.”
Kimmence also shared a post on Instagram in celebration of their upcoming arrival, writing in the caption: “To say I’m grateful is an understatement. Can’t wait to start my perfect little family with you.”
Numerous Instagram users commented underneath the couple’s Instagram posts to wish them congratulations, including several of Dyer’s fellow former Love Island castmates.
“Oh my god,” Samira Mighty commented, leaving a second comment that read: “Love you!!”
“I’M CRYING,” wrote Amber Davies, who won Love Island the year before Dyer, while Demi Jones commented: “Omg!! Congrats.”
Dyer won Love Island in 2018 alongside her ex-boyfriend Jack Fincham.
In January, Fincham made the surprise announcement that he had become a father to a baby girl, called Blossom.
The 28-year-old explained that while he is usually open about his life on social media, he chose to keep “this blessing” a secret.
Dyer and Fincham revealed in April 2019 that they had broken up, eight months after winning the reality dating competition together.
The former couple quickly became favourites to win Love Island in 2018, eventually walking away with the joint £50,000 prize.