The little one is the couple's first child together.
Thicke, 40, is already a father to seven-year-old son, Julian Fuego Thicke, with former wife actor Paula Patton.
The "Dreamworld" singer took to Instagram to introduce his newborn baby girl to the world, who was born on February 22.
He posted a video cradling his daughter with the caption, "On 2/22 at 13:33 Mia Love Thicke was born. Thank you God and April Love."
The couple have been together for over three years.