And they've already taken to Twitter to wish Beyonce Knowles and Jay-Z's little girl Blue Ivy well and congratulate the proud mother and father.
"Welcome to the world princess Carter! Love Aunty Rih," wrote Bajan singer Rihanna, referring to Jay-Z's real name Shawn Corey Carter.
There was also lots of excitement about the news in Gwyneth Paltrow and Chris Martin's household. The two couples are close friends and the Hollywood actress posted: "Welcome to the world Blue! We love you already."
Cheryl Cole wrote: "Congratulations to Beyonce and Jay on the birth of their first child. Welcome to the world Blue Ivy!"
"A Lovely #Congratulations To Beyonce & JayZ For Bringing A Lovely Bundle Of Joy Into The World!!! What A Talent She Will Be!!!" added LaToya Jackson.
P Diddy also shared his joy: "Congrats to jay and B! God Bless :) ! And many more!"
The 30-year-old gave birth to her little one at a New York hospital on Saturday night.
Her 42-year-old husband was by her side during the birth.
A source told the singer's hometown newspaper Houston Chronicle that "mother and baby are doing fine".
Crazy in love: Beyonce and Jay-Z, the intensely private power couple
How an Independent Woman became the queen of the music scene