The star - best loved as MyDaily HQ for her legendary role in There's Something About Mary - wore next to no jewellery, bar a few simple silver rings and a cuff on her right ear. It seems Cam-D has been taking notes from Emma Watson's style handbook.
Her beauty look was equally as played-down with just a flash off pink across her pout and a sweep of mascara.
Co-stars Leslie Mann and Kate Upton also pulled out all the stops for their red carpet appearance. Leslie in a peach and pink two-piece complete with Angelina Jolie-style thigh split, and Kate channelling her inner glitter ball in an embellished tube dress.
"This is something we really need to reframe. The most interesting parts are for women who are over 40. We don't see it that way, because they're not the sexy parts. Look at the Oscar nominees in the last decade.
"We're not giving those women enough credit for what they're accomplishing, which is beautiful performances."
And of hitting the big four one Cam confessed: "It is the best time of my life. I love being this age, are you kidding?"
Fortunately she kept her mouth shut on the pubic hair front this time.
LOVE CAMERON? See more from the blonde bombshell in her style file below.