Jean Reno ...
Léon

Gary Oldman Gary Oldman ...
Stansfield

Natalie Portman Natalie Portman ...
Mathilda

Danny Aiello Danny Aiello ...
Tony

Peter Appel Peter Appel ...
Malky

Willi One Blood Willi One Blood ...
1St Stansfield Man (as Willie One Blood)

Don Creech Don Creech ...
2nd Stansfield man

Keith A. Glascoe Keith A. Glascoe ...
3rd Stansfield man (Benny)

Randolph Scott Randolph Scott ...
4th Stansfield man

Michael Badalucco Michael Badalucco ...
Mathilda's Father

Ellen Greene Ellen Greene ...
Mathilda's Mother

Elizabeth Regen Elizabeth Regen ...
Mathilda's Sister

Carl J. Matusovich Carl J. Matusovich ...
Mathilda's Brother

Frank Senger Frank Senger ...
Fatman

Lucius Wyatt Cherokee Lucius Wyatt Cherokee ...
Tonto (as Lucius Wyatt 'Cherokee')

Eric Challier Eric Challier ...
Bodyguard Chief

Luc Bernard Luc Bernard ...
Mickey

Maïwenn Maïwenn ...
Blond Babe (as Ouin-Ouin)

Jessie Keosian Jessie Keosian ...
Old Lady

George Martin George Martin ...
Receptionist

Abdul Hassan Sharif Abdul Hassan Sharif ...
Mathilda's Taxi driver

Stuart Rudin Stuart Rudin ...
Leon's Taxi driver

Kent Broadhurst Kent Broadhurst ...
1st Policeman

Tommy Hollis Tommy Hollis ...
2nd Policeman

Peter Linari Peter Linari ...
1st Security man

Johnny Limo Johnny Limo ...
2nd Security man

Danny Peled Danny Peled ...
Kid's Leader

Seth Jerome Walker Seth Jerome Walker ...
Pauly

Michael Mundra Michael Mundra ...
Cigarette Kid

Alex Dezen Alex Dezen ...
Ball Kid

Betty Miller Betty Miller ...
Orphanage Headmistress

Geoffrey Bateman Geoffrey Bateman ...
Swat Chief

Arsène Jiroyan Arsène Jiroyan ...
Swat Hostage

Peter Vizard Peter Vizard ...
Doctor

Joseph Malerba Joseph Malerba ...
Stairway Swat

David W. Butler David W. Butler ...
Important Jogger (as David Butler)

Robert LaSardo Robert LaSardo ...
Client #1 (as Robert Lasardo)

Steve Gonnelo Steve Gonnelo ...
3rd Security Guard

William James Stiggers Jr. William James Stiggers Jr. ...
Subway Rapper (as Willie Stiggers Jr.)

Anthony Ragland Anthony Ragland ...
Uniformed Guard

Crystal Michelle Blake Crystal Michelle Blake ...
Girl

Sonny Zito Sonny Zito ...
DEA Security Guards

Rocky Hernandez Rocky Hernandez ...
Cop

Randy Pearlstein Randy Pearlstein ...
Security Guard

Trevor Walace Trevor Walace ...
Policeman

Keith S. Bullock Keith S. Bullock ...
Bodyguard

Jeff McBride Jeff McBride ...
Bodyguard

Fred Fischer Fred Fischer ...
Newspaperman

Peter Justinius Peter Justinius ...
Secret Service

Denis Bellocq Denis Bellocq ...
Jogger

Thomas Delehanty Thomas Delehanty ...
CIA Agent

Ed Ventresca Ed Ventresca ...
Fatman Bodyguard

Wallace Wong Wallace Wong ...
Chinatown Boss

Cary Wong Cary Wong ...
Chinatown Boss' sidekick

Amimul Rolly Amimul Rolly ...
Bellhop #1

Mohammed Rashid Mohammed Rashid ...
Bellhop #2

Adam Busch Adam Busch ...
Manolo

Mario Todisco Mario Todisco ...
Tony's Barber

James Melissinos James Melissinos ...
Girl Chaser

Jernard Burks Jernard Burks ...
Stansfield man (as Jernard Burkes)

Matt De Matt Matt De Matt ...
Stansfield man

Samy Naceri Samy Naceri ...
Swat 1

Christophe Gautier Christophe Gautier ...
Swat 2

Junior Almeida Junior Almeida ...
Swat 3

David Gregg David Gregg ...
Swat 4

Michel Montanary Michel Montanary ...
Swat 5

Hervé Husson Hervé Husson ...
Swat 6

Didier Legros Didier Legros ...
Swat 7

Marc Andréoni Marc Andréoni ...
Swat 8 (as Marc Andreoni)

Gilles Kleber Gilles Kleber ...
Swat 9

Junior John Levis Junior John Levis ...
Swat 10

Tony Sauraye Tony Sauraye ...
Bodyguard 1

Thierry Maurio Thierry Maurio ...
Bodyguard 2

James Fahrner James Fahrner ...
Bodyguard 3

Daniel Schenmetzler Daniel Schenmetzler ...
Bodyguard 4

Rest of cast listed alphabetically:
Jean-Hugues Anglade Jean-Hugues Anglade ...
Cameo Appearance (long version) (uncredited)

Alyssia Dujmovich Alyssia Dujmovich ...
Student (uncredited)

Michael Wehrhahn Michael Wehrhahn ...
Jimmy, SWAT Team Member (uncredited)