InStyle's Top Cover Girl Drew Barrymore Turns 40 Today

Drew Barrymore just joined the 40 club.

That's right! America's sweetheart is ringing in her 40th birthday today. Barrymore, who has been on the cover of InStyle more than any other celebrity (read: seven times, with her most recent being on the record-breaking September 2013 issue that housed a whopping 716 pages!), has impressed us time and time again---first with her acting in rom-coms, action flicks, and dramas, then with her always-chic maternity style. Most recently, however, the star has won us over with her awe-inspiring photography book Find It In Everything, where the mother of two documented the sweetest heart-shaped objects she stumbled upon over the years, as well as with her appreciation of all things beauty made evident by the launch of her cosmetics line, Flower Beauty.

It's been a whirlwind of a career for Barrymore, and the actress-turned-entrepreneur shows no signs of slowing down. In honor of her birthday, we're taking a look back at her changing looks, from up-and-coming child actor to Hollywood A-lister.

PHOTOS: Drew Barrymore's Transformation