Taking to Instagram to show the change, the Pirates of the Caribbean star uploaded two snapshots of the new look.
In the first shot, Penelope looked away from the camera while wearing a beautiful black low-cut top and white faux-fur coat.
The second shot was taken at a much closer angle and showed off her new shoulder-length hair and some luscious red lips.
Star file: Penelope Cruz
In her photo caption, the star teased: "Shooting today with @lancomeoffical #comingsoon."
Penelope's many fans immediately went wild for the new look, lavishing the actress with compliments.
"OH LA LA!!!" enthused one fan, alongside a string of heart-eyed emojis, while another added: "Omg omg omg!!!! I love these pictures!!! You look fabulous."
A third wrote: "Loveeeeee the hair," and a fourth complimented: "This looks amazing. And love the hair."
The Vanilla Sky star was even showered with love for the new look from her celebrity fans, with actress Lily Collins posting: "This hair!!!!"
Penelope showed off her new style
Emile Hersch simply left an open-mouth emoji and Ricky Martin's husband, Jwan Yosef, left a string of heart eyed emojis.
Many of the star's other fans wrote about how beautiful she was, with one saying: "Omg the most beautiful woman in this world, PENELOPE CRUZ YOU SLAY!!!!"
Another added: "To me you are one of the most beautiful women ever!!!!! Charming, sweet, sexy, talented, smart…!"
Penelope has been around hair stylists all of her life, and has in the past helped out friends like Salma Hayek when she was stuck without her glam squad.
Fans adored the transformation
Speaking to InStyle.com, Penelope revealed that she once did Salma's hair and makeup in the dark.
"She had a premiere one night and called me like, 'My glam squad didn't show up, and the power went out in my house. I need you,'" she revealed.
"We put candles everywhere, and I got her ready." Penelope recently wowed her fans when she showed off her beautiful physique in a daring sheer skirt while standing poolside.
The star shared the mesmerising photo on her Instagram and was wearing what appeared to be a shell construction with long sweeping arm holes accentuating her figure.
Fans were at a complete loss at her beauty and were only able to post emojis to show how they felt.
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