The 33-year-old Keeping Up With the Kardashians cast member posted a photo of the baby's nursery revealing the name in the caption.
"Our little girl, True Thompson, has completely stolen our hearts and we are overwhelmed with LOVE," she captioned the photo. "Such a blessing to welcome this angel into the family! Mommy and Daddy loooooove you True!"
Kardashian and Thompson, who met in August 2016 after being introduced by Haqq McCray's sister Malika Haqq, announced that they were expecting a child together in December. Kardashian made the reveal by sharing a black and white photo of her baby bump being embraced by Thompson on Instagram.
"My greatest dream realized!" Kardashian wrote. "We are having a baby! I had been waiting and wondering but God had a plan all along. He knew what He was doing. I simply had to trust in Him and be patient. I still at times can't believe that our love created life!"
She added, "Tristan, thank you for loving me the way that you do! Thank you for treating me like a Queen! Thank you for making me feel beautiful at all stages! Tristan, most of all, Thank you for making me a MOMMY!!! You have made this experience even more magical than I could have envisioned! I will never forget how wonderful you've been to me during this time! Thank you for making me so happy my love!"
The birth of Kardashian's baby, however, came during tough time for the Strong Looks Better Naked author. On April 10, news broke that Thompson had been videotaped kissing a woman at a club in New York City, as well as bringing her back to a hotel. Shortly after that video aired, TMZ published footage from October, when Kardashian would have been three months pregnant, during which he kissed another woman and put his head between the breasts of a third.
The cheating scandal left many wondering whether or not she would give their daughter Thompson's last name, and it looks like the couple did decide to go with Thompson as a surname.
Historically, all of Kardashian's sisters have given their children their respective fathers' last names, even if they weren't married. Kourtney Kardashian's children all have the last name Disick, while Kim Kardashian gave her first daughter, North, the surname West, despite the fact that she was not yet married to Kanye.