The mother of the child is 23-year-old singer songwriter Cat Cavill- real name Catherine Harding- who he had been in a relationship with but recently split.
The musician is reportedly already 5 months along her pregnancy.
A spokesperson for the Hollywood star released a statement confirming the happy news.
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“I can confirm that Jude Law and Catherine Harding are expecting a child together in the spring.
“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, 41, is also dad to sons Rafferty, 17 Rudy, 12 and daughter Iris, 13, with ex-wife Sadie Frost.
Along with his eldest children, he is also dad to 5-year-old daughter Sophia with model Samantha Burke.
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New baby momma Cat was reportedly considering trying out for the X Factor before discovering she was carrying the offspring of Hollywood royalty.
A source told the Daily Mail: “It all happened very quickly. They met a little while ago and fell for one another, then Cat told friends that she was going out to Prague, that's when it emerged that she was in a relationship with Jude.
“Sadly they are no longer a couple but that they are both so determined that the baby will be loved very much by both his or her parents.
“It is easy to see why Jude fell for Cat, she is beautiful, she is the person who when she walks in a room you just think "wow, look at her.’”