Kate Walsh as Dr. Addison Forbes Montgomery
Tim Daly as Dr. Peter Finch
Taye Diggs as Dr. Sam Bennett
Paul Adelstein as Dr. Cooper Freedman
Merrin Dungey as Dr. Naomi Bennett (pilot)
Chris Lowell as William "Dell" Cooper
Audra McDonald as Dr. Naomi Bennett
Amy Brenneman as Dr. Violet Turner
KaDee Strickland as Dr. Charlotte King