Bomer as Bryce Larkin (Season one and two)
Richie as Heather Chandler (season two)
Kreuk as Hannah (season three)
Kurkova as Sofia Stepanova (season four)
Glau as Greta 4 (season four)
Hamilton as Mary Elizabeth Bartowski (season four)
Routh as Daniel Shaw (Season three and five)
Bakula as Stephen Bartowski (season two and three)
Lloyd as Dr. Leo Dreyfus (season three)
Bilson as Lou Palone (Season One)
Monaghan as Tyler Martin (season two)
Hamill as Jean Claude (season 5)
Munn as Greta (season four)
Dalton as Alexei Volkoff/Hartley Winterbottom (season four)