The couple announced the happy news with a pair of adorable photos on Instagram.
"Welcome sweet Annie," Harris, 38, wrote next to a pic of her newborn daughter snoozing on her daddy's arm. "Justin and I had the best date night ever ... a little golf, a little party in the delivery room, a little push, and a new little one to love!"
Pasutto shared his own photo of himself tenderly kissing Annie's forehead. "Hello (world), I'm Annie," he wrote in the caption.
Members of Bachelor Nation were quick to respond to Harris' happy news.
"Congratulations mama!!!! So happy for you and your growing family," wrote original "Bachelorette" star Trista Sutter in the comments section of Harris' pic.
"Congrats! Lots of love to you and your family," wrote the show's season-seven star Ashley Rosenbaum.
Jade Roper, from season 19 of "The Bachelor," couldn't help remarking on little Annie's sweetness, gushing, "She's beautiful!"
Harris and Pasutto are also parents to a son named Leo.
In May, Harris shared a special family portrait to announce she and Pasutto were expecting a little girl. The sweet pic found the trio (and their pooch) decked out in pink.
"My heart could EXPLODE!!!! Up next ... a baby GIRL!!!! @justinpasutto, are you ready for this!!??" she wrote in the caption.
Congrats to Jillian and Justin on their sweet new bundle of joy!