"I can confirm the arrival of Jude Law and Catherine Harding's daughter," the rep revealed in a statement. "Both are delighted and continue to ask that their privacy and that of their child be respected."
Despite no longer being in a relationship, they were, the rep said, "both wholeheartedly committed to raising their child."
Harding, 23, is an aspiring British singer who dated Law for a few months in mid-2014.
The Sherlock Holmes actor is already dad to sons Rafferty, 18, and Rudy, 12, and daughter Iris, 14, whom he shares with ex-wife Sadie Frost. He also has a daughter Sophia, 5, with ex-girlfriend Samantha Burke.