Cameron Diaz and Benji Madden have welcomed their first child together.

The 47-year-old actress and the Good Charlotte rocker have become first time parents to a daughter named Raddix Madden, and have taken to social media to share the happy news with their followers.

In a joint statement posted to Instagram, they wrote: ''Happy New Year from the Maddens! We are so happy, blessed and grateful to begin this new decade by announcing the birth of our daughter, Raddix Madden.''

The couple - who married in 2015 - went on to gush over their new arrival, saying she has ''instantly captured'' their hearts.

But the pair insisted they won't be sharing any images of their tot, because they want to ''protect'' her ''privacy''.

They added: ''She has instantly captured our hearts and completed our family. While we are overjoyed to share this news, we also feel a strong instinct to protect our little one's privacy. So we won't be posting pictures or sharing any more details, other than the fact that she is really really cute!! Some would even say RAD:)

''From our family to all of yours, we're sending our love and best wishes for a Happy New Year and Happy New Decade...

''Sincerely,

''Cameron&Benji (sic)''

Since the couple began dating in 2014, they've both been notoriously private about their love life.

However, Cameron previously said she wouldn't be putting any pressure on herself to become a mother, as the universe would let her know if it was meant to be.

She said: ''I just kind of like how things unravel and life kind of reveals itself to you. And I've just never been in the place where I was like, 'Right now is the time I'm supposed to have a baby.' But I do want my own family eventually, however that comes to me, whether it's through adoption or [through another method].''