The 24-year-old confirmed the news on Wednesday after posting a black and white image to her Instagram story showing her newborn.
She captioned the sweet picture, “dreams do come true”, adding a red love heart emoji.
The influencer first announced her pregnancy in February this year after dating her boyfriend, 30, for two years.
Burton also took to his Instagram story to post a sweet tribute to his girlfriend, writing “Very proud of you, we are both lucky to have you.”
Tomlinson is known as the younger sister of singer and former One Direction member, Louis Tomlinson. She is a make-up artist, model, author and businesswoman with the self-tanning company, Tanologist.
The 24-year-old has suffered the loss of two close family members in recent years - her mother, Johannah Deakin, died from leukaemia in 2016 aged 43, and her sister Felicité just two years later at the age of 18.
Burton has also suffered, having previously dated Caroline Flack, who took her own life in 2020.
The new parents reportedly bonded over their grief and grew closer over the years, and now have a spark of joy of their own.