The 32-year-old supermodel gave birth on Wednesday to a girl they named Vivian, according to the Boston Globe. Further details about the birth have yet to be released.
"We feel so lucky to have been able to experience the miracle of birth once again and are forever grateful for the opportunity to be the parents of another little angel. Vivian Lake was born at home on December 5. She is healthy and full of life," the Brazilian beauty wrote on her official Facebook page, alongside an adorable photo of her holding her daughter's tiny hand.
"Thank you all for your support and well wishes. We wish you and your families many blessings."
Gisele and Tom first announced they were expecting their second child in August.
The couple already have a son -- Benjamin Brady -- who will be celebrating his third birthday this weekend.
In addition, the New England Patriots hunk, 35, also has a five-year-old son John with his former girlfriend, actress Bridget Moynahan.
Gisele and Tom began dating in 2006, after her split from actor Leonardo DiCaprio after a five-year relationship.
The couple tied the knot in February 2009 in a private ceremony in Santa Monica, California, and in April they renewed their vows in Costa Rica in a larger ceremony for friends and family.