To take down South Boston's Irish Mafia, the police send in one of their own to infiltrate the underworld, not realizing the syndicate has done likewise. While an undercover cop curries favor with the mob kingpin, a career criminal rises through the police ranks. But both sides soon discover there's a mole among them.
Leonardo DiCaprio
Matt Damon
Jack Nicholson
Mark Wahlberg
Martin Sheen
Ray Winstone
Vera Farmiga
Anthony Anderson
Alec Baldwin
Kevin Corrigan
James Badge Dale
David O'Hara
Mark Rolston
Robert Wahlberg
Kristen Dalton
Thomas B. Duffy
Richard Hughes
J.C. MacKenzie
Mary Klug
Peg Holzemer
Robert 'Toshi' Kar Yuen Chan
Gurdeep Singh
Armen Garo
John Cenatiempo
Joseph Riccobene
Billy Smith
Lyman Chen
Kevin P. McCarthy
Chris Fischer
Brian Smyj
William Severs
Larry Mitchell
Anthony Estrella
Andrew Breving
Tracey Paleo
Douglas Crosby
Dorothy Lyman
Audrie Neenan
Frank Mallicoat
Paula DeMers
Conor Donovan
Amanda Lynch
Sallie Toussaint
Patrick Coppola
Mick O'Rourke
Deborah Carlson
Nellie Sciutto
Peter Welch
Henry Yuk
Dennis Lynch
Michael Byron
William Lee
John Rue
Peter Crafts
Joseph P. Reidy
John Farrer
Paris Karounos
Brian Haley
Terry Serpico
Jay Giannone
John Polce
Bo Cleary
David Conley
Victor Chan
Jill Brown
Sarah Fearon
Denece Ryland
Daniel F. Risteen, Jr.
Francis P. Hughes
Johnny Cicco
Chance Kelly
Shay Duffin
John McConnell
Kenneth Stoddard
Jeffrey Winter
Paddy Curran
Mark Philip Patrick
David Fischer
Walter Y.F. Wong
Tony M. Yee
Francesca Scorsese
Alex Morris
Emma Tillinger Koskoff
Craig 'Radio Man' Castaldo
Takumi Bando
Eric Bruno Borgman
Brendan Burke
Chris Chinn
Jeffrey Corazzini
Jim Ford
Trudi Goodman
Steve Lord
Jack McCullough
Osmani Rodriguez
Lawrence Cameron Steele
Conor Timmis
Joseph Oliveira
Adam Masnyk
John Franchi
Paul McGillicuddy
Kim Carrell
Rebecca Love