The actress and Honest Company shared a fun video celebrating her birthday milestone on Wednesday.
Set to Anne-Marie's "Birthday," Alba is seen enjoying an outdoor party with balloons, tasty food, friends and cupcakes.
"It's my birthday. I'ma do what I like. I'ma eat what I like. I'ma kiss who I like. It's my birthday
I'ma do what I like. I'ma wear what I like. I'ma party tonight," the lyrics say as the video montage plays.
"#Thisis40 🎉🍾🎈," the Honey star captions the clip. Fans and friends congratulated her and wished her a happy birthday in the comments section.
The actress-turned-entrepreneur recently opened up about her stepping back from acting while at the "top of her career." In a new interview with Romper, she said that after welcoming her first child, daughter Honor, in 2008, her mindset changed.
After giving birth, she felt like she needed to do "something bigger," also sharing how her mom's cancer and her own battle with chronic illness made her have "this real moment of, I want to live, and thrive, and spend as much time with this little person that I'm bringing into the world as possible and stay."
"I felt like if I was going to have this platform, then what can I do with it that could be meaningful and make a difference?" she expressed. "That just felt so real when I became a mom for the first time."
See more in Alba in the video below.