The star announced the news on Instagram with a photo of a baby’s hand wrapped around her thumb.
Hilton wrote, "You are already loved beyond words 💙.”
People magazine reports Paris and Carter recently welcomed a boy via surrogate.
She also told the magazine, "It's always been my dream to be a mother and I'm so happy that Carter and I found each other. We are so excited to start our family together and our hearts are exploding with love for our baby boy."
Kim Kardashian was among the well wishers in the comments, writing, "So happy for you guys!!! 🤍"
Her mom Kris Jenner weighed in with, "Congratulations what a blessing!!!!! We love you!!!! ❤️🙏😍❤️"
Chrissy Teigen, who just welcomed her third child, shared, "A BABY!!!!! congratulations so happy for you both!!"
Demi Lovato posted, "Congratulations sis!!!!"
Heidi Klum told her, "I am Sooooooo happy for you . Sending lots and lots of love ❤️."
Hilton, who wed Carter in November 2021, had been open about wanting to start a family and going through the in vitro fertilization process.
In December, “Extra’s” Terri Seymour spoke with Paris and she hinted at baby plans in 2023.
Hilton teased, “Stay tuned… We always wanted to start our family in 2023 so yes, that will be very soon.” As for documenting motherhood like she did with her wedding, Paris said, “I will definitely be capturing it.”
Back in September 2021, she told Terri what kind of mom she will be.
“I’m probably going to be a strict mom,” she said. She also revealed a possible name for her future child, adding, “I’m just worried for when my baby London says, ‘Mom, I want to go on a date, I want go to a club,’ and I’m going to go, ‘No.’”