| Dominic West | Det. James 'Jimmy' McNulty |
| John Doman | Dep. Comm. for Operations William A. Rawls |
| Idris Elba | Russell 'Stringer' Bell |
| Frankie Faison | Acting Commissioner Ervin H. Burrell |
| Aidan Gillen | Councilman Thomas 'Tommy' Carcetti |
| Wood Harris | Avon Barksdale |
| Deirdre Lovejoy | Asst. State's Atty. Rhonda Pearlman |
| Clarke Peters | Det. Lester Freamon |
| Wendell Pierce | Det. William 'Bunk' Moreland |
| Lance Reddick | Lt. Cedric Daniels |
| Andre Royo | Reginald 'Bubbles' Cousins |
| Sonja Sohn | Det. Shakima 'Kima' Greggs |
| Jim True-Frost | Det. Roland 'Prez' Pryzbylewski |
| Robert Wisdom | Maj. Howard 'Bunny' Colvin |
| Seth Gilliam | Sgt. Ellis Carver |
| Domenick Lombardozzi | Det. Thomas 'Herc' Hauk |
| J.D. Williams | Preston 'Bodie' Broadus |
| Michael Kenneth Williams | Omar Little |
| Corey Parker Robinson | Det. Leander Sydnor |
| Glynn Turman | Mayor Clarence V. Royce |
| Amy Ryan | Off. Beatrice 'Beadie' Russell |
| Chad L. Coleman | Dennis 'Cutty' Wise |
| Jamie Hector | Marlo Stanfield |
| Leo Fitzpatrick | Johnny Weeks |
| Michael Hyatt | Brianna Barksdale |
| Michael Potts | Brother Mouzone |
| Anwan Glover | Slim Charles |
| Christopher Mann | Councilman Anthony 'Tony' Gray |
| Cleo Reginald Pizana | Chief of Staff Coleman Parker |
| Frederick Strother | State Delegate Odell Watkins |
| Maria Broom | Marla Daniels |
| Shamyl Brown | Donette |
| Brandy Burre | Theresa D'Agostino |
| Richard Burton | Sean 'Shamrock' McGinty |
| Dravon James | Grace Sampson |
| Michael Willis | Andy Krawczyk |
| Justin Burley | Justin |
| Brandon Fobbs | Fruit |
| DeAndre McCullough | Lamar |
| Felicia Pearson | Felicia 'Snoop' Pearson |
| Ernest Waddell | Dante |
| Brian Anthony Wilson | Det. Vernon Holley |
| Gbenga Akinnagbe | Chris Partlow |
| Mia Arnice Chambers | Squeak |
| Norris Davis | Vinson |
| Melvin Jackson Jr. | Bernard |
| Melvin T. Russell | Jamal |
| William Zielinski | Gene |
| Edward Bernard Green Jr. | Spider |
| Michael Kostroff | Maurice 'Maury' Levy |
| Jay Landsman | Lt. Dennis Mello |
| Marty Lodge | Banisky |
| Ryan Sands | Off. Lloyd 'Truck' Garrick |
| Gregory L. Williams | Det. Michael Crutchfield |
| Megan Anderson | Jen Carcetti |
| Tray Chaney | Malik 'Poot' Carr |
| Richard DeAngelis | Col. Raymond Foerster |
| Derren Fuentes | Lt. Torret |
| Tony D. Head | Maj. Bobby Reed |
| Reid Sasser | Director of National Drug Control Policy |
| Michael Ahl | Narcotics Detective |
| Muhammad Ali | Self |
| Chris Bauer | Frank Sobotka |
| Mayo Best | Gerard |
| Perry Blackmon | Perry |
| Benjamin Busch | Off. Anthony Colicchio |
| Alana Campbelle | Mayor's Secretary |
| Enrique Chicas | Bailiff |
| Kahil Dotay | Undercover Street Cop |
| Aaron Fiore | Uniformed Cop With Beer |
| Lawrence Gilliard Jr. | D'Angelo Barksdale |
| Cleve Gray | Crime Scene Technician |
| De'Rodd Hearns | Herbert De'Rodd 'Puddin' Johnson |
| Sheila Hennessey | TV Reporter |
| Raw Leiba | Stringer's Bodyguard |
| Collin Leonard | Dennis Harper |
| Paul Majors | Off. MacGaul |
| Aaron Marcus | State's Attorney |
| David L. Marston | Newspaper Photographer |
| Kerry Meushaw | TV Reporter - Blue Van |
| Manny Oliverez | News Cameraman |
| Karl Otter | District Commander |
| Floyd Patterson | Self |
| Dirk Pratt | Narcotics Detective |
| Doug Roberts | State's Attorney Steven Demper |
| Daniel Ross | Camera Assistant Channel 11 News |
| Jennifer Rouse | Carcetti Campaign Office Staff |
| Michael Salconi | Off. Michael 'Sanny' Santangelo |
| Kurt L. Schmoke | Health Commissioner |
| William Shipman | Detective Western District |
| Darrell M. Smith | Off. Turner |
| David J. Smolar | Newspaperman #2 |
| Rico Sterling | Tyrell |
| Brandan T. Tate | Sapper |
| Jerry Walsh | Mr. Lake |