The famous couple confirmed the news to fashion magazine, Vanity Fair.
Known for being private about their personal life, Pharrell and Helen kept tight-lipped about the details of their three little ones, such as the sex and names of their bundles of joy. But they did reveal that three siblings were born earlier this month.
The pair first confirmed news of their pregnancy to People magazine back in September, but gave no inkling that there would be more than one baby. But it seems Pharrell and Helen have gone from being parents of one to parents of four!
The couple are already parents to son Rocket, who was born in 2008.
Pharrell, 43, explained to Oprah the reasoning behind their son's name, 'In the same way the Indians named their children after a force or animal or element, we named him after a man-made machine that was meant to go up, meant to ascend.'
E!News reported previously that the pair have 'been wanting another child for a while'.
Pharrell and Helen married in 2013 and have made no secret of how much they enjoy being married, with Pharrell being quoted as saying, 'The bestie thing is awesome. Every night is like a sleepover.'
Pharrell, who is known for his musical hits like Blurred Lines and Happy, has also branched out into publishing, and last year released a children's book inspired by his number one hit.
He has also used his creative platform i am OTHER to collaborate with stationery company Yoobi on a back to school range. E!News reported his motivation for the collaboration stemmed from his father-son relationship with Rocket.
Pharrell commented on the project, saying 'I had the future in mind... There is huge necessity of community that we just don't have'.
Congratulations to the new family of six!