Biel gave birth to a son, Silas Randall Timberlake, their reps told People magazine today.
ABC News has reached out to their reps but hasn't heard back yet.
This comes just months after the singer made it official on his Instagram that he and his wife were expecting.
"Thank you EVERYONE for the Bday wishes! This year, I'm getting the GREATEST GIFT EVER. CAN'T WAIT. #BoyOrGirl #YouNeverKnow #WeDontEvenKnow #WeAreTakingBets," he wrote next to a pic of him kissing her stomach.
Timberlake, 34, and Biel, 33, who have been together since 2007, were married on October 19, 2012, in Italy.
The former NSYNC star actually serenaded his bride as she walked down the aisle on their special day.
"I figured if there was something I was going to be able to offer, it would be to sing her down the aisle," Timberlake told Hello. "Grown men were weeping."
Biel told "Good Morning America" in 2012 that taking on the role of a mom in "Playing for Keeps" definitely made her think about having a child one day.
"Yeah sure, especially because the kid Noah that played my son is literally the coolest kid I've ever met," she said, adding that the best part of being married to Timberlake was, "it feels like nothing's changed, yet everything has changed. It's kind of that intangible thing. But I guess the idea of having sort of a partner in crime and I guess the word 'husband' is pretty amazing."