Jesse Eisenberg as Mark Zuckerberg

Andrew Garfield as Eduardo Saverin

Armie Hammer as Cameron Winklevoss / Tyler Winklevoss

Josh Pence as Tyler Winklevoss (Body Double)

Justin Timberlake as Sean Parker

Max Minghella as Divya Narendra

Brenda Song as Christy Lee

Rashida Jones as Marylin Delpy

John Getz as Sy

David Selby as Gage

Denise Grayson as Gretchen

Douglas Urbanski as Larry Summers

Rooney Mara as Erica Albright

Bryan Barter as Billy Olsen

Dustin Fitzsimons as Phoenix Club President

Joseph Mazzello as Dustin Moskovitz

Patrick Mapel as Chris Hughes

Toby Meuli as Phoenix Member Playing Facemash

Alecia Svensen as Girl at Phoenix Club

Jami Owen as Student Playing Facemash

James Dastoli as Student Playing Facemash

Robert Dastoli as Student Playing Facemash

Scotty Crowe as Student Playing Facemash

Jayk Gallagher as Student Playing Facemash

Marcella Lentz-Pope as Erica's Roommate

Trevor Wright as B.U. Guy in Bra

Barry Livingston as Mr. Cox

Marybeth Massett as Mrs. Cox

Randy Evans as Student in Communications Office

Carrie Armstrong as Court Reporter

Henry Roosevelt as Henry

Pamela Roylance as Ad Board Chairwoman

Brian Palermo as CS Lab Professor

Brett Leigh as Phoenix Club Hazer

Chris Gouchoe as Phoenix Club Pledge

Nicholas Tubbs as A Capella Group

Kevin Chui as A Capella Group

Richie Ferris as A Capella Group

Burke Walton as A Capella Group

Nguyen Anh Tuan as A Capella Group

Inbal Amirav as Model

Dane Nightingale as A Capella Group

Stephen Fuller as A Capella Group

John He as A Capella Group

Nick Smoke as KC's Friend

Cali Fredrichs as KC's Friend

Shelby Young as KC

Steve Sires as Speaker / Bill Gates

Melise as Alice Cantwel

Victor Z. Isaac as Stuart Singer

Abhi Sinha as Vikram

Mark Saul as Bob

Cedric Sanders as Reggie

Dakota Johnson as Amelia Ritter

Nancy Linari as Larry Summers' Secretary

Inger Tudor as Anne

Aaron Sorkin as Ad Executive

Mariah Bonner as Tori

Kyle Fain as Intern Eric

Christopher Khai as Intern Ian

Emma Fitzpatrick as Sharon

Jeffrey Thomas Border as Andrew

Courtney Arndt as Victoria's Secret Model

Felisha Terrell as Beautiful Woman

Zoe De Toledo as Harvard Rowers' Coxman

Simon Barr as Harvard Rower

Alex Leigh as Harvard Rower

Phil Turnham as Harvard Rower

Richie Steele as Harvard Rower

Chris Friend as Harvard Rower

Tom Harvey as Harvard Rower

Alex Olijnyk as Hollandia Rowers' Coxman

Ray Poulter as Hollandia Rower

Bob Hewitt as Hollandia Rower

Dave Lambourn as Hollandia Rower

James Padmore as Hollandia Rower

Sebastian Kouba as Hollandia Rower

Charles Herbert as Hollandia Rower

Robin Dowell as Hollandia Rower

Nathan Hillyer as Hollandia Rower

James Shanklin as Prince Albert

Alex Reznik as Prince Albert's Aide

John Hayden as Howard Winklevoss

Oliver Muirhead as Mr. Kenwright

Shane Adler as Stoned Girl

Amy Ferguson as Stoned Girl

Monique Edwards as Bank Teller

Cayman Grant as Peter Thiel's Assistant

Wallace Langham as Peter Thiel

Scott Lawrence as Maurice

Peter Holden as Facebook Lawyer

Darin Cooper as Facebook Lawyer

Jared Hillman as Mackey

Caitlin Gerard as Ashleigh

Lacey Beeman as Sorority Girl

Cherilyn Wilson as Sorority Girl

Caleb Landry Jones as Fraternity Guy

Franco Vega as Policeman

Andrew Thacher as Policeman

Adina Porter as Gretchen's Associate (uncredited)

Jeff Martineau as Bobby's Friend (uncredited)

Noah Baron as Student (uncredited)

Ki Hong Lee as Student (uncredited)

Jesse Heiman as Student (uncredited)

David Broyles as Student Playing Facemash (uncredited)

Mike Bash as Bob (uncredited)

Tony Calle as Harvard Student (uncredited)

Cooper Conley-Currier as Pheonix Club Hazee (uncredited)

Elliott Ehlers as Harvard Student (uncredited)

Brett A. Newton as Harvard Student (uncredited)

Nathan Dean Snyder as Harvard Student (uncredited)

Kristen Clement as Party Girl (uncredited)

Tatum Miranda as Party Girl (uncredited)

Chad Davis as B.U. Guy in Bra #2 (uncredited)

Tony DeSean as Waiter (uncredited)

Vincent Rivera as Waiter (uncredited)

Jason Flemyng as Regatta Spectator (uncredited)

Carlos Foglia as MIT Student (uncredited)

Bryan Forrest as Popular Harvard Student (uncredited)

Jessica Franz as Sorority Girl (uncredited)

Eli Jane as Dancer (uncredited)

Sara Murphy as Dancer (uncredited)

Kandis Mak as Go-Go Dancer (uncredited)

Eric La Barr as Harvard Note-Passer (uncredited)

Naina Michaud as Final Club Girl (uncredited)

Riley Voelkel as Final Club Girl (uncredited)

Tia Robinson as Club Waitress (uncredited)

Jeff Rosick as Dorm Room Guy #2 (uncredited)

Alexandra Ruddy as Ruby Skye Waitress (uncredited)

Adrienne Rusk as Club 66 Girl (uncredited)

Rebecca Tilney as Art History Professor (uncredited)

Georgina Tolentino as Club-Goer (uncredited)