1.) Stars
2.) Recurring Guest Stars
3.) Guest Stars
| Tom Welling | Clark Kent |
| Kristin Kreuk | Lana Lang |
| Michael Rosenbaum | Lex Luthor |
| Allison Mack | Chloe Sullivan |
| Samuel L. Jones III | Pete Ross |
| Annette O'Toole | Martha Kent |
| John Schneider | Jonathan Kent |
| John Glover | Lionel Luthor |
| Eric Johnson (2001-2002) | Whitney Fordman |
| Actor/Actress Name | Character Name | Episodes |
|---|---|---|
| Hiro Kanagawa | Principal Kwan |
|
| Joe Morton | Dr. Steven Hamliton |
|
| Kelly Brook | Victoria Hardwick |
|
| Sarah-Jane Redmond | Aunt Nell |
|
| Tom O'Brien | Roger Nixon |
|
| Actor/Actress Name | Character Name | Episode(s) |
|---|---|---|
| Aaron Douglas | Deputy Birdego | Obscura |
| Adam Brody | Justin Gaines | Crush |
| Adrian McMorran | Jeremy Creek | Pilot |
| Amy Adams | Jodi Melville | Craving |
| Azura Skye | Amy | Shimmer |
| Brandy Ledford | Stepmom | Stray |
| Cameron Dye | Sam Phelan |
|
| Chad E. Donella | Greg Arkin | Metamorphosis |
| Corin Nemec | Jude Royce | Zero |
| Cynthia Ettinger | Martha Kent | First Pilot |
| Dan Lauria | Coach Walt Arnold | Hothead |
| Darrin Klimek | Deputy Gary Watts | Obscura |
| Donna Bullock | Pamela Jenkins | Crush |
| Eric Christian Olsen | Young Harry | Hourglass |
| Gabrielle Rose | Greg's Mother | Metamorphosis |
| George Coe | William Clark | Redux |
| George Murdock | Old Harry | Hourglass |
| Gregory Sporleder | Kyle Tippet | Hug |
| Gwynyth Walsh | Mrs. Moore | Nocturne |
| Jackie Burroughs | Cassandra Carver | Hourglass |
| Jada Stark | Stray | |
| Jason Connery | Dominic Sanatori |
|
| Jonathan Taylor Thomas | Ian | Dichotic |
| Judy Tylor | Amanda Rothman | Zero |
| Kett Turton | Jeff (Amy's Brother) | Shimmer |
| Kevin McNulty | Eric's Dad | Leech |
| Krista Allen | Desiree Atkins-Luthor/Alison Sanders | Heat |
| Lizzy Caplan | Tina Greer | Visage |
| Maggie Lawson | Chrissy Parker | Redux |
| Mark McConchie | Mr. Ellis | X-Ray |
| Michael Coristine | Sean Kelvin | Cool |
| Michael Tomlinson | U.S. Marshal | Red |
| Reynaldo Rosales | Reynaldo Rosales | |
| Richard Gant | Principal Reynolds | Redux |
| Richard Moll | Mr. Moore | Nocturne |
| Rick Peters | Bob Rickman | Hug |
| Rnelson Brown | Lex's Doctor | Hug |
| Robert Wisden | Gabe Sullivan |
|
| Ryan Kelley | Ryan |
|
| Sara Downing | Jessie Brooks | Red |
| Sean Faris | Byron Moore | Nocturne |
| Shawn Ashmore | Eric | Leech |
| Sheila Moore | Reaper | |
| Shonda Farr | Sasha | Drone |
| Simon Wong | Paul Chan | Drone |
| Tania Saulnier | Jenna | Cool |
| Tony Todd | Earl Jenkins | Jitters |
| William B. Davis | Mayor Tate | Ryan |