The pitter-patter of little feet rang out in 2012, as plenty of famous faces -- including music divas, A-list actors and hard partying reality stars -- welcomed babies into the family, and RadarOnline.com has the run down on all the little bundles of joy that emerged over the year.
Among the most heralded births had to be musical mega-stars Beyonce and Jay-Z welcoming their first child together, a girl named Blue Ivy. In typical grandiose fashion, the child's name was a trending topic on Twitter within moments of her arrival being announced.
A few bonafide headliners were also productive -- make that reproductive, as Oscar winner Reese Witherspoon had her first child with her second hubby, Jim Toth, while another Academy Award winner, Robert Downey Jr. welcomed his second son -- 19 years after he first became a dad.
Here are all of the big celeb births in the year that was 2012:
Beyonce and Jay-Z
Music icons Beyonce and Jay-Z welcomed their first child, daughter Blue Ivy, on January 7. In an entry on Beyonce's website, the proud parents wrote that their daughter's "birth was emotional and extremely peaceful" and that they're "in heaven" over the news. "She was delivered naturally at a healthy 7 lbs and it was the best experience of both of our lives."
Robert Downey Jr. and Susan Downey
Ironman star Robert Downey Jr. and his wife Susan welcomed their son Exton Elias February 7. The rehabilitated bad boy has a 19-year-old son, actor Indio, from his former marriage to Deborah Falconer.
Hilary Duff and Mike Comrie
Singer Hilary Duff and her hockey hubby of two years, Mike Comrie, welcomed son Luca Cruz March 20. She tweeted, "Welcome to the World Luca Cruz Comrie! Tuesday evening, we became proud parents of a healthy 7 pound 6 ounce beautiful boy … We are overjoyed and feel like the luckiest parents in the world. He is surrounded by so much love!!"
Bruce Willis and Emma Heming
Die Hard star Bruce Willis and stunning model wife Emma Heming welcomed their first child, daughter Mabel Ray on April 1. Their rep said they were "overjoyed about the newest member of their family." Bruce has three girls -- Rumer, Scout and Tallulah -- with ex-wife Demi Moore.
Jack Osbourne and Lisa Stelly
Reality star Jack Osbourne and Lisa Stelly welcomed their first baby, daughter Pearl, April 24. Jack's mother Sharon, calling it a "life changing experience," tweeted, "Today I witnessed my first grandchild being born … she is an angel." Jack and Lisa subsequently tied the knot in Hawaii in October.
Jessica Simpson and Eric Johnson
Fashion Star's Jessica Simpson and fiance Eric Johnson had their first kid May 1, a girl named Maxwell Drew Johnson. Jessica said on their website, "We are so grateful for all of the love, support and prayers we have received. This has been the greatest experience of our lives!!" The blonde beauty subsequently lost 60 pounds as a Weight Watchers spokesperson following the birth.
Kourtney Kardashian and Scott Disick
Reality stars Kourtney Kardashian and Scott Disick's welcomed their second child (and first daughter) Penelope Scotland July 8. After giving son Mason a playmate, Kourtney wrote, "Scott and I are overjoyed to welcome our precious angel … into our lives. We are forever blessed."
Uma Thurman and Arpad Busson
Pulp Fiction stunner Uma Thurman and boyfriend Arpad Busson had their first child, daughter Rosalind Arusha Arkadina Altalune Florence Thurman-Busson, July 15. Rosalind's the third child for both partners: Uma has two kids, Maya and Levon, with ex-husband Ethan Hawke, while Arpad has two kids, Arpad Flynn Alexander and Aurelius Cy Andrea with his one-time fiancee Elle Macpherson.
Kristin Cavallari and Jay Cutler
The Hills star Kristin Cavallari and Chicago Bears QB Jay Cutler welcomed their first child, son Camden Jack Cutler, August 8. She tweeted, "We are thrilled to welcome Camden Jack Cutler into the world. He was born this morning weighing 7lbs 9oz. Everyone is doing great!"
Nicole "Snooki" Polizzi and Jionni LaValle
Jersey Shore star Nicole "Snooki" Polizzi and her fiance, Jionni LaValle, welcomed son Lorenzo Dominic August 26. The proud reality star tweeted afterwards, "I am SO IN LOVE with my son Lorenzo Dominic! I had my little man last night, healthy at 6lbs! HE'S MY WORLD! <3." Snooki and Jionni have been engaged since March.
Reese Witherspoon and Jim Toth
Perennial A-lister Reese Witherspoon and Jim Toth welcomed their first baby together, son Tennessee James, on September 27. The boy is Reese's third child, as she has daughter Ava and son Deacon from her previous marriage to Cruel Intentions co-star Ryan Phillippe.
For the ultimate in-depth celebrity baby run down, including pages and pages of super cute photos, pick up the OK magazine special, Hollywood's Cutest Kids, on newsstands now!