| Malin Akerman | Laurie Jupiter / Silk Spectre II |
| Billy Crudup | Dr. Manhattan / Jon Osterman |
| Matthew Goode | Adrian Veidt / Ozymandias |
| Jackie Earle Haley | Rorschach |
| Jeffrey Dean Morgan | Edward Blake / Comedian |
| Patrick Wilson | Dan Dreiberg / Nite Owl |
| Carla Gugino | Sally Jupiter / Silk Spectre |
| Matt Frewer | Moloch |
| Stephen McHattie | Hollis Mason |
| Laura Mennell | Janey Slater |
| Rob LaBelle | Wally Weaver |
| Gary Houston | John McLaughlin |
| James M. Connor | Pat Buchanan (as James Micheal Connor) |
| Mary Ann Burger | Eleanor Clift |
| John Shaw | Doug Roth |
| Robert Wisden | Richard Nixon |
| Jerry Wasserman | Detective Fine |
| Don Thompson | Detective Gallagher |
| Frank Novak | Henry Kissinger |
| Sean Allan | NORAD General |
| Garry Chalk | NORAD General |
| Ron Fassler | Ted Koppel |
| Stephanie Belding | Janet Black |
| Michael Kopsa | Paul Klein |
| William S. Taylor | Prison Psychiatrist (as William Taylor) |
| Chris Burns | Dumb Thug |
| Malcolm Scott | Fat Thug |
| Danny Wattley | Huge Prisoner |
| Nhi Do | Vietnamese Girl |
| Walter Addison | Lee Iacocca |
| Keith Martin Gordey | Auto CEO |
| David MacKay | Child Murderer (as David Mackay) |
| Fulvio Cecere | Agent Forbes |
| Ted Cole | Dick Cavett |
| Mark Acheson | Large Man At Happy Harry's |
| John B. Destry | Happy Harry's Bartender (as John Destry) |
| Chris Gauthier | Seymour (as Christopher Gauthier) |
| L. Harvey Gold | New Frontiersman Editor |
| Jay Brazeau | News Vendor |
| Jesse Reid | Teenager at Newsstand |
| Manoj Sood | Karnak Scientist |
| Dan Payne | Dollar Bill |
| Niall Matter | Mothman |
| Apollonia Vanova | Silhouette |
| Glenn Ennis | Hooded Justice |
| Darryl Scheelar | Captain Metropolis |
| Clint Carleton | Young Hollis Mason |
| Mike Carpenter | Young Moloch |
| Leah Gibson | Silhouette's Girlfriend |
| Brett Stimely | John F. Kennedy |
| Carrie Genzel | Jackie Kennedy |
| Greg Travis | Andy Warhol |
| Greg Armstrong-Morris | Truman Capote |
| Andrew Colthart | Naked Man At Warhol Party |
| Bruce Crawford | Bank Robber |
| Sal Sortino | 1940 Watchmen Photographer (as Salvatore Sortino) |
| Eli Snyder | Young Rorschach |
| Lori Watt | Rorschach's Mother |
| Tony Bardach | John With Rorschach's Mother |
| John Kobylka | Fidel Castro |
| Carmen Lavigne | Anti War Protester |
| J.R. Killigrew | David Bowie |
| Steven Stojkovic | Mick Jagger |
| Martin Reiss | Brezhnev |
| Frank Cassini | Sally's Husband |
| John R. Taylor | Priest |
| Tara Frederick | Aggressive Hooker |
| Daryl Shuttleworth | Jon's Father |
| Jaryd Heidrick | Young Jon |
| Ron Chartier | Carnival Photographer |
| Carly Bentall | Wally's Girlfriend |
| Matt Drake | Older Boy Bully |
| Haley Guiel | Laurie - 13 Years (as Haley Adrianna Guiel) |
| Sonya Salomaa | Adrian Veidt's Assistant |
| Tyler McClendon | Veidt Enterprises Security Guard |
| Salli Saffioti | Annie Leibovitz |
| Neil Schell | Man In Riot Crowd |
| Michael Eklund | Man In Riot Crowd |
| Deborah Finkel | Woman In Riot Crowd |
| Louis Chirillo | Face To Face TV Producer |
| Marsha Regis | Face To Face TV Receptionist |
| Patrick Sabongui | Knot Top Gang Leader |
| John Tench | Knot Top Gang Member |
| Santo Lombardo | Knot Top Gang Member |
| Jason Schombing | NY SWAT |
| Darren Shahlavi | NY SWAT |
| Marshall Virtue | NY SWAT |
| Colin Lawrence | Officer Kirkpatrick |
| Chris Weber | Officer O'Brien |
| Alessandro Juliani | Rockefeller Military Base Technician |
| Alison Araya | Foreign Newscaster |
| Sahar Biniaz | Foreign Newscaster (as Sahar) |
| Matthew Harrison | Foreign Newscaster |
| Bernadeta Wrobel | Foreign Newscaster |
| Youri Obryvtchenko | Foreign Newscaster |
| Heidi Iro | Foreign Newscaster |
| Kit Koon | Foreign Newscaster |
| Parm Soor | Foreign Newscaster |
| Cristina Menz | Foreign Newscaster |
| Lynn Colliar | Foreign Newscaster |
| Tony Ali | Foreign Newscaster |
| Katie Bennison | Foreign Newscaster |
| Ian Farthing | Foreign Newscaster |
| Calvin Lee | Foreign Newscaster |
| Alexander Mandra | Foreign Newscaster (as Alexander Sasha Mandra) |
| Isabelle Champeau | Foreign Newscaster |
| Ashley O'Connell | Foreign Newscaster |
| Mark Gash | On Location Reporter |
| Suzanne Clements-Smith | On Location Reporter |
| Agam Darshi | On Location Reporter |
| Tom McBeath | News Analyst |
| Kevin McNulty | News Anchor |
| Mark Docherty | Newscaster |
| Clay St. Thomas | Newscaster |
| Dale Wolfe | Keene Act Anchor |
| Ken Tremblett | Keene Act Anchor |
| Dawn Chubai | Keene Act Anchor |
| Manuelita Kinsley | Keene Riot Reporter |
| Tamara Stanners | Vietnam 51st State Anchor |
| Sahara Davis | Young Tenement Fire Child (as Sahara xOasis Ashanti Davis) |
| Greig Hospes | Tenement Fire Child |
| Danny Hospes | Tenement Fire Child |
| Ali Dunn | Tenement Fire Child |
| Jeffrey Flieler | Tenement Fire Policeman |
| Kurt Evans | Tenement Fire News Reporter |
| Sylvesta Stuart | Destruction Firefighter |
| Terence Kelly | General West |
| Mi-Jung Lee | A Bomb Test Anchorwoman |
| Ted Friend | Larry Culpeper |
| Tiffany Burns | News Reporter |
| Michael Adamthwaite | Bar Knot Top |
| Damon Caro | U.S. Soldier (uncredited) |
| Douglas Chapman | Roy Chess (uncredited) |
| Trevor Coppola | NY Swat #4 (uncredited) |
| Dave Cote | Man at Club (uncredited) |
| Saira De Goede | Girl at Club (uncredited) |
| Ed Metzger | Prof. Albert Einstein (uncredited) (unconfirmed) |
| Yoosik Oum | Scientist (uncredited) |
| Kennith Overbey | Village People Cop (uncredited) |
| Zack Snyder | Commando in Vietnam (uncredited) (unconfirmed) |
| Michael Stevens | Doomsday Clock Scientist #1 (uncredited) |
| Danny Woodburn | Big Figure Prisoner (uncredited) |