Billy Campbell
Dr. Alan Farragut (26 eps)
Meegwun Fairbrother
Daniel Aerov (26 eps)
Jordan Hayes
Dr. Sarah Jordan (26 eps)
Mark Ghanimé
Major Sergio Balleseros (26 eps)
Neil Napier
Dr. Peter Farragut (26 eps)
Kyra Zagorsky
Dr. Julia Walker (26 eps)
Hiroyuki Sanada
Dr. Hiroshi Hataki (26 eps)
Robert Naylor
Spencer (16 eps)
Cat Lemieux
Dr. Doreen Boyle (13 eps)
Steven Weber
Brother Michael (13 eps)
Matt Long
Dr. Kyle Sommer (13 eps)
Cristina Rosato
Leila Weisner (13 eps)
Alison Louder
Sister Amy (13 eps)
Severn Thompson
Sister Anne (13 eps)
Alison Louder
Sister Amy (13 eps)
Sarah Booth
Sister Olivia (9 eps)
Amber Goldfarb
Jaye (6 eps)
Jeri Ryan
Constance Sutton (3 eps)
Christian Jadah
Lt. Klein (3 eps)
Julian Bailey
Lt. Humphries (3 eps)
Tamara Brown
Dr. Sulemani (2 eps)
Erica Anderson
Grace (1 eps)
Patrick Baby
Dr. Duchamp (1 eps)