The Oscar-nominated actor and his former partner Catherine Harding announced the news via a statement.
"I can confirm that Jude Law and Catherine Harding are expecting a child together in the spring", read the statement which was released by Jude's representative.
It continued: "Whilst they are no longer in a relationship, they are both wholeheartedly committed to raising their child. They consider this a private matter and other than this confirmation no statement will be made. I ask that you respect the privacy of all parties involved and their families."
Jude has a five-year-old daughter Sophia, from his relationship with Samantha Burke, and three children from his marriage to Sadie Frost - Rafferty, 18, Iris, who turns 14 this month, and 12-year-old Rudy.
In 2009 Jude opened up on being a father to Parade magazine. He said: "Being a daddy is what counts.
"I used to sleep until noon, but it’s not so bad to have to get up at 7 and give them breakfast. My daughter made me realise that if there’s anything that’s going to make a man of you, it’s having your will broken by a little girl."
Despite ending their marriage in 2003, Sadie and Jude regularly prove that they're still great friends, and in September posed for a family photo with their children to celebrate son Rudy's birthday.
The image shows the group around a table laden with football-adorned cupcakes and other treats, while Sadie and Rafferty put their arms around birthday boy Rudy.
His eldest son Rafferty recently made his catwalk debut, walking the runway for DKNY Men during London Collections: Men.
The 18-year-old took centre stage during the opening night of the men's fashion week, looking cool in a baggy ensemble from the New York label, while dad Jude, who is the face of Dior Homme Sport, watched the catwalk show from the front row.