Horizon Season 1

Main characters

 * Kiefer Sutherland as Colonel John Grant (22/22 episodes)
 * Ashley Scott as Commander Sivea Ve'nal (22/22 episodes)
 * Ben Browder as Major Chase Reynolds (22/22 episodes)
 * Carlos Bernard as Captain David Connor (/22 episodes)
 * Rachael Leigh Cook as Christine Summers (22/22 episodes)
 * Dion Johnstone as Doctor Tom Galloway (22/22 episodes)
 * And Andrew J. Robinson as Doctor Lenori (20/22 episodes)

Recurring characters

 * Phillip Rhys as Doctor Yusuf Naiyeer (14/22 episodes)
 * Scott MacDonald as Sivok (9/22 episodes)
 * John M. Jackson as General Francis Williams (8/22 episodes)
 * Steven Culp as Lt. Commander/Commander Day'ek Sonak (6/22 episodes)
 * Sentinel Commander (6/22 episodes)
 * Daniel Dae Kim as Major Hikaru Sato (5/22 episodes)
 * Lieutenant MacFarley (4/22 episodes)
 * Lieutenant Adams (3/22 episodes)
 * Melinda Clarke as Nebulan Woman (3/22 episodes)
 * Kardos (3/22 episodes)
 * Melanos (3/22 episodes)
 * Jack Gwaltney as Mediator Dureg (3/22 episodes)
 * Lieutenant/Captain Jacques Beaumont (2/22 episodes)
 * Jude Ciccolella as Ambassador Ca'vel (2/22 episodes)
 * Gregory Itzin as Minister Kalos (2/22 episodes)
 * Molly Brink as Loral / Kardos (2/22 episodes)
 * Lieutenant Kendrick (2/22 episodes)
 * Roger Cross as Kor'Etan Gorlon (2/22 episodes)
 * Dion Luther as Mollem (2/22 episodes)
 * Commander Elin (2/22 episodes)
 * Commander Seeta (2/22 episodes)
 * Michael Shanks as the voice of Thor (2/22 Episodes)

Guest Stars

 * Christopher Judge as Teal'c (1/22 episodes)
 * Amanda Tapping as Colonel Samantha Carter (1/22 episodes)
 * Colin Cunningham as Lt. Colonel Paul Davis (1/22 episodes)