Matt Damon

Rory

Casey Affleck

Cobby

Ving Rhames

Frank Toomey

Jack Harlow

Scalvo

Michael Stuhlbarg

Mr. Besegai

Alfred Molina

Richie Dechico

Owen Earls

Charlie Haggerty

Hong Chau

Dr. Donna Rivera

Natalie Carter

Mrs. Haggerty

Walter Liebman

Terry

André De Shields

Mr. Kelly

Ron Perlman

Mayor Miccelli

Rob Gronkowski

Rob Gronkowski

Toby Jones

Attorney Alan Flynn

Slate Holmgren

Dave Wedge

Ronnie Cho

Mark Choi

Sheika Murray

Waiter #1 at Wharf

Perry Strong

Waiter #2 at Wharf

Nick Trice

City Hall Employee

Tommy Nohilly

Police Commissioner

Jason Furlani

Cabinet Member

David Gborie

Bouncer

Toby Onwumere

John Wayne

Paul Walter Hauser

Booch

Scout Backus

Colani

Nicholas B Alexander

Sergeant at Rivera's Office

Nathaniel Wood

Massachusetts Trooper #1

Craig Hutchinson

Massachusetts Trooper #2

Mike Bash

Boston Police Officer

Deirdre McCourt

Vermont Cop

Shawn Fitzgibbon

Quincy Cop

Jerry Kernion

Fire Monitor

Nik Walker

Hero Fireman

Ramona Floyd

Bartender

Mark Steven Dancewicz

Tactical Cop

Brett Keating

Sniper in Tower

Michael Rodrick

Police on the Roof

Eleni Yiovas

Senior Tactical Cop

Gregory Cunningham

Senior Cop at Plaza

Peter Morse

Cop at Barricade

Robert Marsella

Cop That Says Hey

Don DiPetta

Officer at Airport

Chris Roach

Police Transfer Officer

Billy Smith

New Police Commissioner

John Noble Barrack

Photographer

Jadon Cole

Rory's Son

Robbie Dema

Border Patrol Mountie #1

Robert Harvey

Border Patrol Mountie #2

Jonathan Gabriel Charles

Pollster

Craig 'Radio Man' Castaldo

Self (uncredited)