Pop diva Beyonce Knowles has given birth to a baby girl in New York City, reports say.

The songstress and her husband Jay-Z welcomed their first child after a scheduled C-section on Saturday night, E! News wrote.

So, what name have the "King and Queen of Hip-Hop" picked for their progeny?

Proud daddy Jay-Z is reportedly telling friends that the baby's name is Blue Ivy Carter, according to E! But several other outlets have said the name is Ivy Blue Carter.

Representatives for Beyonce and Jay-Z, whose real name is Shawn Carter, have yet to clear up the confusion.

Meanwhile, high-profile well-wishers and fans alike have flooded the Twittersphere to congratulate the couple.

"Welcome to the world princess Carter! Love Aunty Rih," wrote singer Rihanna.

Music mogul Russell Simmons piped in as well, typing "congrats to my good friends Beyonce and Jay-Z."

By late Sunday morning, the music power couple was trending on the Twitter as fans around the world learned of Baby Carter's arrival.

"Bet she's a beautiful baby!" surmised user LauraSxoxo.

Another user referenced Beyonce's song "Run the World (Girls)" in her message of congratulations.

"She's gonna run the world like her momma," wrote lesleygabriel.

Last September, the 30-year-old singer let it slip that she was six-months pregnant while shooting a music video, leading many to expect a December birth.