The first-time father, 30, shared the news via Twitter on Sunday.
Our little angel is here! She was born on Feb. 6th. Daddy now has two loves in his life! Thank you all for the love and support :)— Stephen Stagliano (@StephenStag) February 9, 2014
Pappas later retweeted the message.
The 32-year-old former Bachelorette first announced she was pregnant in August, telling Us Weekly that both she and Stagliano were "so thrilled to be welcoming our baby Stag."
"We cannot wait to make memories with this baby, love it unconditionally, and to teach him or her to play soccer!" she continued. "We have looked forward to this moment for a very long time and we are so happy to share this exciting news with everyone!!"
After her participation in season 11 of the ABC reality television show and accepting a marriage proposal from professional snowboarder Jesse Csincsak, the reality star called off the relationship and went on to participate in another reality series titled Get Married on Lifetime TV. Pappas became engaged to Stagliano in August 2010. The two married in October 22, 2011.