Zuckerberg Tops Fortune’s 40 Under 40 List

This year Facebook CEO Mark Zuckerberg ranks first on the Fortune 40 under 40 list, moving up a spot to displace 2010’s top pick, his mentor Marc Andreessen, who no longer qualifies.

Following Zuckerberg in the No. 2 spot is Google CEO Larry Page, who’s been broken out from his usual pairing with co-founder Sergey Brin. Brin’s down at No. 11 this year, followed by fellow Googler Marissa Mayer at No. 20.

Entirely absent from the 2011 list are Twitter co-founders Evan Williams and Biz Stone, who shared the No. 3 spot in 2010. They’ve since left the company and are back undercover working on new start-up projects together at Obvious.

Other featured techies this year include Jack Dorsey of Square and Twitter (8), Spotify’s Daniel Ek (18), Groupon’s Andrew Mason (27), Foursquare’s Dennis Crowley (28), Dropbox’s Drew Houston and Arash Ferdowski (29), Facebook’s Carolyn Everson (35), Opower’s Dan Yates and Alex Laskey (36), and Instagram’s Kevin Systrom (39).

The 40 under 40 issue hits newsstands on Oct. 24.