Tommy Lee Jones as Kay

Will Smith as Jay

Rip Torn as Zed

Lara Flynn Boyle as Serleena

Johnny Knoxville as Scrad / Charlie

Rosario Dawson as Laura Vasquez

Tony Shalhoub as Jeebs

Patrick Warburton as Agent Tee

Jack Kehler as Ben

David Cross as Newton

Colombe Jacobsen-Derstine as Hailey

Peter Spellos as Motorman

Michael Rivkin as Man with Dog

Michael Bailey Smith as Creepy

Lenny Venito as New York Guy

Howard Spiegel as New York Guy

Alpheus Merchant as MIB Guard

Jay Johnston as Agent

Joel McKinnon Miller as Agent

Derek Cecil as Repairman Agent

Sean Rouse as MIB Agent

Peter Spruyt as MIB Customs Agent

Kevin Cotteleer as MIB Customs Agent

Marty Belafsky as MIB Customs Agent

Rick Baker as MIB Passport Control Agent

Martha Stewart as Martha Stewart

Michael Jackson as Agent M

Sid Hillman as Agent Gee

Tom Whitenight as Agent C

Nick Cannon as MIB Autopsy Agent

Andre Blair as Central Park Agent

Jeremy Howard as Bird Guy Alien / Postal Sorting Alien

Mary Stein as Bird Lady Alien

Martin Klebba as Family Child Alien

John Alexander as Jarra / Family Dad Alien

Denise Cheshire as Family Mom / Locker Alien

Ernie Grunwald as Young Postal Employee

Chloe Sonnenfeld as Young Girl at Post Office

John Andrew Berton Jr. as Split Alien Guy

William E. Jackson as Eye Guy

Doug Jones as Joey

Biz Markie as Rapping Alien

Peter Graves as Peter Graves

Linda Kim as Ambassador Lauranna

Paige Brooks as "Mysteries in History" Lauranna

Stephanie Kemp as Neuralyzed Mother

Barry Sonnenfeld as Neuralyzed Father

Victoria Jones as Neuralyzed Daughter

Michael Garvey as Corn Face

Michael Dahlen as Flesh Balls

Kevin Grevioux as Pineal Eye

Derek Mears as Mosh Tendrils

Sonny Tipton as Dog Poop

John Richardson as Postman

Philip Goodwin as Diner Guy

Tim Blaney as Frank the Pug (voice)

Greg Ballora as Sleeble (voice)

Carl J. Johnson as Gleeble (voice)

Thom Fountain as Neeble (voice)

Brad Abrell as Mannix (voice)

Richard Pearson as Gordy (voice)

Rick Avery as Subway Passenger (uncredited)

Michael Beardsley as Suspicious Video Store Patron (uncredited)

Michael Buonomo as College Student (uncredited)

Kristin Charney as Family Mom (uncredited)

Patrick Coleman Duncan as 'History's Mysteries' Alien (uncredited)

Darrell Foster as MIB Autopsy Agent (uncredited)

Ned Gorman as Cockroach on Sidewalk (voice) (uncredited)

Gene LeBell as Subway Passenger (uncredited)

Pete Macnamara as Man in Black (uncredited)

Drew Massey as Worm Guy (uncredited)

Matthew McGrory as Tall Alien (uncredited)

Christopher Metas as Alien Accountant (uncredited)

Bart Mixon as Alien Puppeteer (uncredited)

Alexandra O'Hara as Diner Waitress (uncredited)

David Patykewich as Bald Kid Alien (uncredited)

Martin Pfefferkorn as Homeless Alien Collaborater (uncredited)

David C. Roehm Sr. as Alien (uncredited)

Leo Rogstad as New Yorker on His Cell (uncredited)

Thomas Rosales Jr. as Subway Passenger (uncredited)

Brandee Sanders as Subway Business Woman (uncredited)

Hannah Sim as Head-Bobbing Alien (uncredited)

Peter Siragusa as Mayor of Grand Central Terminal Locker Aliens (voice) (uncredited)

Daniel Browning Smith as Aquarium Boy (uncredited)

Brian Steele as Sharkmouth (uncredited)

Mark Steger as Quadraped Alien (uncredited)

Alan Tuskes as Lobsterhead Alien (uncredited)

Shannon Watson as 70's MIB Agent (uncredited)

Bo Welch as Astronaut (uncredited)