Jessica Alba and husband Cash Warren welcomed their third child, a baby boy, on New Year's Eve.

The former Dark Angel star announced her exciting news via Instagram.

'Hayes Alba Warren 12/31/17 Best gift to ring in the New Year!!' the mum-of-three captioned the photo.

 

Hayes Alba Warren 12/31/17 Best gift to ring in the New Year!! Cash and I feel so blessed. Haven and Honor are already obsessed with their new baby bro.  #familyof5

A post shared by Jessica Alba (@jessicaalba) on Jan 1, 2018 at 11:05am PST

'Cash and I feel so blessed. Haven and Honor are already obsessed with their new baby bro,' the 36-year-old gushed.

He's the first baby boy in the family-of-five, joining big sisters Haven, 6, and Honor, 9.

Proud papa Cash also shared a photo of Hayes on Instagram. 

 

Hayes Alba Warren: You sure know how to ring in the new year! You showed up a few days early but we couldn’t be any happier. Your Mamma is the strongest woman I know … you’re so lucky to have her by your side. You have two amazing sisters who already adore you and I know you’ll be thankful to have them guide the way. On your first day of life, I promise to love you, to cherish you, and to provide you with a sandbox full of dreams to explore. Welcome to the family my sweet baby Hayes! 12/31/2017

A post shared by Cash Warren (@cash_warren) on Jan 1, 2018 at 11:51am PST

The 38-year-old lovingly wrote to his son: 'On your first day of life, I promise to love you, to cherish you, and to provide you with a sandbox full of dreams to explore.'

Fans took to the comments to congratulate the actress.

Welcome to the world, baby Hayes.