시즌 정규 출연진 15

1. 

   Dominic West

   Jimmy McNulty

2. 

   Lance Reddick

   Cedric Daniels

3. 

   Sonja Sohn

   Kima Greggs

4. 

   Wood Harris

   Avon Barksdale

5. 

   Wendell Pierce

   Bunk Moreland

6. 

   Idris Elba

   Stringer Bell

7. 

   Deirdre Lovejoy

   Rhonda Pearlman

8. 

   Clarke Peters

   Lester Freamon

9. 

   Andre Royo

   Bubbles

10. 

    Frankie Faison

    Ervin Burrell

11. 

    John Doman

    William Rawls

12. 

    Lawrence Gilliard Jr.

    D'Angelo Barksdale

13. 

    Paul Ben-Victor

    Spiros "Vondas" Vondopoulos

14. 

    Amy Ryan

    Beatrice "Beadie" Russell

15. 

    Chris Bauer

    Frank Sobotka

특별출연 19

1. 

   Michael Kenneth Williams

   Omar Little

2. 

   Michael Kostroff

   Maurice 'Maury' Levy

3. 

   Callie Thorne

   Elena McNulty

4. 

   Pablo Schreiber

   Nick Sobotka

5. 

   Chris Ashworth

   Sergei 'Serge' Malatov

6. 

   Charley Scalies

   Thomas 'Horseface' Pakusa

7. 

   Melanie Nicholls-King

   Cheryl

8. 

   Fredro Starr

   Marquis 'Bird' Hilton

9. 

   Lev Gorn

   Eton Ben-Eleazer

10. 

    Michael Hyatt

    Brianna Barksdale

11. 

    James Ransone

    Chester 'Ziggy' Sobotka

12. 

    Wendy Grantham

    Shardene Innes

13. 

    Domenick Lombardozzi

    Detective Thomas 'Herc' Hauk

14. 

    Jim True-Frost

    Detective Roland 'Prez' Pryzbylewski

15. Erik Dellums

    Dr. Randall Frazier

16. 

    Robert F. Chew

    Joseph 'Proposition Joe' Stewart

17. 

    Luray Cooper

    Nathaniel 'Nat' Coxson

18. 

    Seth Gilliam

    Sergeant Ellis Carver

19. Susan Rome

    Asst. State's Atty. Ilene Nathan

제작진 2