This is the first child for the 27-year-old singer and her music executive husband.
"Christina and Jordan are proud to announce the birth of their son Max Liron Bratman. He is a beautiful, healthy baby boy!" a rep for the couple tells PEOPLE. "Mom is resting and doing well!"
Despite various media reports that Aguilera had her baby on Friday, Max – 6 lbs. 2 oz. and 20.5 inches long – arrived late Saturday night in L.A.
In a message later posted on her official Web site Sunday, Aguilera tells fans, "Today is a very joyful and special day for Jordan and I as we welcome our first son into this world."
The singer also posted a special video of her song "Save Me from Myself," with footage from the couple's personal wedding video.
"Just a little something to say 'thank you' for your undying love and support," writes Aguilera. "It is in no small part because of you that I live such a blessed and wonderful life!"
Paris Hilton First Confirms PregnancyAlthough Aguilera didn't announce the gender of her baby while she was pregnant, she celebrated the bundle of joy's pending arrival with a blue-themed baby shower in November.
The singer, who was mum on her pregnancy for months despite rumors and a visible bump, officially confirmed she was expecting in November – eight weeks after Paris Hilton prematurely spilled the beans at the LAX nightclub in Las Vegas. "Congratulations to the most beautiful pregnant woman in the world. You're gorgeous," Hilton announced to a crowded room, stunning Aguilera and Bratman.
Later in November, Aguilera bared her growing belly on the cover of Marie Claire. In the article, she revealed that although she'd wanted to have a baby, it happened sooner than she'd expected, following a visit from Bratman while she was on tour last April.
"You've heard it takes some time – except with Power Egg and Super Sperm here," she said. "I'm like, 'Oh my God, can you believe it just happened?' "
Aguilera also addressed her silence on the matter in the earlier stages of her pregnancy, telling the magazine, "Because I hadn't said anything, people thought I was trying to keep it this big, bad secret, and that's not the case at all. I just wasn't commenting. I'm not being like, 'Hey, everybody, I'm pregnant!' I'm not that girl."
Married to Bratman since November 2005, Aguilera had babies on her mind back in July 2006, when she said on Britain's GMTV morning show, "In five years' time I'd probably like to start thinking about a child." Now, she's gotten her wish – just a little bit earlier than she expected.
Photo Special: See Christina's Baby Bump Style
For more news, go to www.christinaaguilera.com
Reporting by ULRICA WIHLBORG