|
| Sam Jones III: | Pete Ross (seasons 1-3) |
|
| Eric Johnson: | Whitney Fordman (season 1) |
| Patrick Bergin: | Morgan Edge (season 3) |
| Kelly Brook: | Victoria Hardwick (season 1) |
| Patrick Cassidy: | Henry Small (season 2) |
| Jason Connery: | Dominic Sanatori (seasons 1 & 2) |
| Martin Cummins: | Dr. Gardner (seasons 2 & 3) |
| William B. Davis: | Mayor William Tate (seasons 2 & 3) |
| Cameron Dye: | Sam Phelan (season 1) |
| Rutger Hauer: | Morgan Edge (season 2) |
| Gary Hudson: | FBI Agent Frank Loder (season 3) |
| Hiro Kanagawa: | Principal Kwan (season 1) |
| Ryan Kelley: | Ryan James (seasons 1 & 2) |
| Mitchell Kosterman: | Sheriff Ethan (seasons 1 & 2) |
| Rob LaBelle: | Dr. Frederick Walden (season 2) |
| Michael McKean: | Perry White (season 3) |
| Camille Mitchell: | Sheriff Nancy Adams (seasons 2 & 3) |
| Joe Morton: | Dr. Steven Hamilton (seasons 1 & 2) |
| Tom O'Brien: | Roger Nixon (season 1) |
| Sarah-Jane Redmond: | Aunt Nell Potter (seasons 1 & 2) |
| Christopher Reeve: | Dr. Virgil Swann (seasons 2 & 3) |
| Ian Somerhalder: | Adam Knight (season 3) |
| Terence Stamp: | Jor-El (seasons 2 & 3) |
| Emmanuelle Vaugier: | Dr. Helen Bryce (seasons 2 & 3) |
| Paul Wasilewski: | Lucas Luthor (season 2) |
| Robert Wisden: | Gabe Sullivan (seasons 1-3) |
| Françoise Yip: | Dr. Lia Teng (season 3) |
