Leonardo DiCaprio

• Billy

Matt Damon

• Colin

Jack Nicholson

• Costello

• Actor

Mark Wahlberg

• Dignam

Martin Sheen

• Queenan

Ray Winstone

• Mr. French

Vera Farmiga

• Madolyn

Anthony Anderson

• Brown

Alec Baldwin

• Ellerby

Kevin Corrigan

• Cousin Sean

James Badge Dale

• Barrigan

David O'Hara

• Fitzy

Mark Rolston

• Delahunt

Robert Wahlberg

• Lazio (FBI)

Kristen Dalton

• Gwen

Thomas B. Duffy

• Govenor

Richard Hughes

• Uncle Edward

J.C. MacKenzie

• Realtor

Mary Klug

• Billy's Aunt

Peg Holzemer

• Mrs. Kennefick

Robert 'Toshi' Kar Yuen Chan

• Triad Boss

Gurdeep Singh

• Pakistani Proprietor

Armen Garo

• Providence Gangster #1

John Cenatiempo

• Providence Gangster #2

Joseph Riccobene

• Kneecapped Bankrobber

Billy Smith

• Detective #1 Tailing Queenan

Lyman Chen

• Translator

Kevin P. McCarthy

• Detective #1 - Colin's Unit

Chris Fischer

• Detective #2 - Colin's Unit

Brian Smyj

• Man Glassed in Bar

William Severs

• Older Priest

Larry Mitchell

• Younger Priest

Anthony Estrella

• Police Camera Tech

Andrew Breving

• Police Cell Phone Tech

Tracey Paleo

• Darlene the Secretary

Douglas Crosby

• Man Killed by French

Dorothy Lyman

• Woman at Bar #1

Audrie Neenan

• Woman at Bar #2

Frank Mallicoat

• News Anchor

Paula DeMers

• Billy's Mother

Conor Donovan

• Young Colin

Amanda Lynch

• Carmen

Sallie Toussaint

• Woman at Opera

Patrick Coppola

• Bookie Harassed by French

Mick O'Rourke

• Jimmy Bags

Deborah Carlson

• Sister Mary Theresa

Nellie Sciutto

• Queenan's Secretary

Peter Welch

• Other Prisoner

Henry Yuk

• Chinese Government Man

Dennis Lynch

• Costello's Crew #1

Michael Byron

• Costello's Crew #2

William Lee

• Costello's Crew #3

John Rue

• Luncheonette Proprietor

Peter Crafts

• Man in Costello's Bar

Joseph P. Reidy

• Priest w/ Young Colin

John Farrer

• Priest at Billy's Funeral

Paris Karounos

• Jimmy Pappas

Brian Haley

• Detective #2 Tailing Queenan

Terry Serpico

• Detective #3 Tailing Queenan

Jay Giannone

• Detective #4 Tailing Queenan

John Polce

• Lynn Detective

Bo Cleary

• Drill Instructor #2 (voice)

David Conley

• Gang Member with Mr. French

Victor Chan

• Chinese Delivery Man

Jill Brown

• Executed Woman

Sarah Fearon

• French's Wife

Denece Ryland

• Woman Doctor

Daniel F. Risteen, Jr.

• Crack House Cop #1

Francis P. Hughes

• Crack House Cop #2

Johnny Cicco

• Crack Addict

Chance Kelly

• Exam Instructor

Shay Duffin

• Bartender at Brasserie

John McConnell

• Bookie in Costello's Bar

Kenneth Stoddard

• State Trooper #1

Jeffrey Winter

• State Trooper #2

Paddy Curran

• New Guy

Mark Philip Patrick

• New Guy

David Fischer

• Executed Man

Walter Y.F. Wong

• Waiter in Alley

Tony M. Yee

• Waiter in Alley

Francesca Scorsese

• Little Girl at Airport

Alex Morris

• Young Man at Airport

Emma Tillinger Koskoff

• Woman with Dog

Craig 'Radio Man' Castaldo

• Crack House Denizen

Takumi Bando

• Triad (uncredited)

Eric Bruno Borgman

• Reporter (uncredited)

Brendan Burke

• Irish Thug (uncredited)

Chris Chinn

• Gang Member (uncredited)

Jeffrey Corazzini

• Crime Scene Unit (uncredited)

Jim Ford

• Cadet (uncredited)

Trudi Goodman

• Woman Office Worker (uncredited)

Steve Lord

• Academy Pistol Coach (uncredited)

Jack McCullough

• EMT (uncredited)

Osmani Rodriguez

• Reporter (uncredited)

Lawrence Cameron Steele

• Academy Firearms Instructor (uncredited)

Conor Timmis

• Rugby Fan (uncredited)

Joseph Oliveira

• Officer (uncredited)

Adam Masnyk

• Southie Teen / Soccer Player (uncredited)

John Franchi

• Pedestrian (uncredited)

Paul McGillicuddy

• Subway Passenger (uncredited)

Kim Carrell

• MA State Police Detective

Rebecca Love

• Adult Film Actress (uncredited)