In an Instagram post, Mahomes revealed the couple's daughter, Sterling Skye Mahomes, was born Saturday and weighed 6 pounds, 11 ounces.
The couple each posted a photo of their daughter holding Matthews' finger as she wore a "Sterling" necklace.
Patrick Mahomes told reporters in the week leading up to Super Bowl LV against the Tampa Bay Buccaneers that the due date was "coming up pretty quickly."
A day after the Chiefs' loss to the Buccaneers, the 2018 NFL Most Valuable Player said one of his off-season goals was to prepare for fatherhood.
"I've got to work on becoming a better dad, even though I haven't become one yet," he said.
Mahomes and Matthews got engaged on Sept. 1, 2020, the same day the Chiefs received their championship rings for defeating the San Francisco 49ers in Super Bowl LIV. Mahomes proposed to Matthews in a private suite at Arrowhead Stadium.
Later that month, the couple revealed that Matthews was pregnant. Nearly a month later, they announced in a gender reveal that they were having a daughter.