The iconic supermodel has teamed up with the cosmetics brand to become their first-ever global ambassador, and has said it's an "absolute honour" to be chosen for the inaugural role.
She said in a statement: "It's an absolute honour to be the new and first official face of Pat McGrath Labs. Pat is my chosen family and an undeniable creative force in the beauty business who has been in my life since the early stages of my career. Pat has created a line that brings fantasy and glamour back into our daily lives and makes us dream again! There is no one else I'd rather embark on this journey with other than the iconic Pat McGrath."
Naomi, 50, has been working with Pat McGrath for over two decades since they met on the set of an i-D photoshoot with Kate Moss in 1994, and have combined creative forces in a number of projects from international runways to fashion editorials.
And the beauty says the pair had an instant connection.
She told Vogue.com: "I knew right away that I loved her personality. But I also felt safe - she's very maternal and makes you feel comfortable right away - and confident that she knew what she was doing. I was so happy to work with a makeup artist of colour because there weren't many at the time. Moving forward, I wanted to work with her on everything I possibly could."
Pat, also 50, is equally as pleased to unveil Naomi as the first face of her brand, as she praised the model's "unparalleled work ethic and sublime soul".
In her own statement, the makeup artist said: "I am thrilled that my sister Naomi Campbell is our first official face. Naomi's beauty is without compare, but what truly makes her special, and the ultimate McGrath Muse, is her legendary loyalty, unparalleled work ethic and sublime soul.
"It is an understatement to say that I consider myself blessed to call her a friend. To be a part of her luminous legacy as a trailblazer in the worlds of beauty and fashion, is truly an honour."