Cast Overview

===Faculty===
*Debbie Allen as Lydia Grant
*Albert Hague as Benjamin Shorofsky
*Carol Mayo Jenkins as Elizabeth Sherwood (seasons 1-5)
*Ann M. Nelson as Mrs. Gertrude Berg (Seasons 1-6)
*Ken Swofford as Quentin Morloch (Seasons 3- 5.09)
*Graham Jarvis as Principal Bob Dyrenforth (Seasons 5.10- 6)
*Morgan Stevens as David Reardon (season 2, recurring seasons 3 & 4)
*Eric Pierpoint as Paul Seeger (Season 6.03)
*Michael Thoma as Greg Crandall (Season 1)
===Students===
*Gene Anthony Ray as Leroy Johnson
*Carlo Imperato as Danny Amatullo (Seasons 1-6)
*Billy Hufsey as Christopher Donlon (seasons 3-6)
*Valerie Landsburg-McVay as Doris Schwartz (seasons 1-4)
*Jesse Borrego as Jesse Velasquez (seasons 4-6)
*Lee Curreri as Bruno Martelli (seasons 1-3)
*Cynthia Gibb as Holly Laird (seasons 3-5)
*Nia Peeples George as Nicole Chapman (seasons 4-6)
*Erica Gimpel as Coco Hernandez (seasons 1-3,recurring Seasons 4-6)
*Loretta Chandler as Dusty Tyler (seasons 5-6)
*Lori Singer as Julie Miller (seasons 1-2)
*Carrie Hamilton as Reggie Higgins (seasons 5-6)
*Janet Jackson as Cleo Hewitt (season 4)
*Michael Cerveris as Ian Ware (season 6)
*Elisa Heinsohn as Jillian Beckett (season 6)
*P.R. Paul as Montgomery MacNeil (season 1, final episode of season 6)
*Page Hannah as Kate Riley (seasons 5)
*Olivia Barash as Maxie Sharp (season 6)
===Additional characters===
*Dick Miller as Lou Mackie (season 6, recurring previously on seasons 4 & 5)
*Stephanie E. Williams as Stephanie Harrison (season 2)
===Recurring characters===
*Carmine Caridi as Angelo Martelli (seasons 1–2)
*Michael DeLorenzo as Michael (seasons 1–3)
*Denny Dillon as Corky (season 6)
*David Greenlee as Dwight Mendenhall (seasons 2–5)
*Robert Romanus as Miltie Horowitz (seasons 5–6)
*Carolyn J. Silas as Laura Mackie (season 6)
*Sam Slovick as Cassidy (season 4)
*Bronwyn Thomas as Michelle (season 1–4)
*Caryn Ward as Tina Johnson (seasons 5–6)