This page is a list of main characters that appeared in the opening credits of at least one episode of each season.

Season One

• James Spader as Alan Shore
• Monica Potter as Lori Colson
• Rhona Mitra as Tara Wilson
• Lake Bell as Sally Heep
• Mark Valley as Brad Chase
• William Shatner as Denny Crane
• Rene Auberjonois as Paul Lewiston
• Candice Bergen as Shirley Schmidt

Season Two

• James Spader as Alan Shore
• Mark Valley as Brad Chase
• Julie Bowen as Denise Bauer
• Rene Auberjonois as Paul Lewiston
• Justin Mentell as Garrett Wells
• Ryan Michelle Bathe as Sara Holt
• Candice Bergen as Shirley Schmidt
• William Shatner as Denny Crane

Season Three

• James Spader as Alan Shore
• Julie Bowen as Denise Bauer
• Mark Valley as Brad Chase
• Rene Auberjonois as Paul Lewiston
• Craig Bierko as Jeffrey Coho
• Constance Zimmer as Claire Simms - joined cast in 3x08
• Gary Anthony Williams as Clarence Bell - joined cast in 3x11
• Candice Bergen as Shirley Schmidt
• William Shatner as Denny Crane

Season Four

• James Spader as Alan Shore
• John Larroquette as Carl Sack
• Christian Clemenson as Jerry Espenson
• Gary Anthony Williams as Clarence Bell
• Tara Summers as Katie Lloyd
• Saffron Burrows as Lorraine Weller
• Taraji P. Henson as Whitney Rome
  
• Candice Bergen as Shirley Schmidt
• William Shatner as Denny Crane

Season Five

• James Spader as Alan Shore
• John Larroquette as Carl Sack
• Christian Clemenson as Jerry Espenson
• Tara Summers as Katie Lloyd
  
• Candice Bergen as Shirley Schmidt
• William Shatner as Denny Crane