| Person: | Characters | Episodes | |
| • John Nolan (3) | played | 24 Episodes | |
| • Enrico Colantoni | played | 19 Episodes | |
| • Robert John Burke | played | 17 Episodes | |
| • Al Sapienza | played | 13 Episodes | |
| • Boris McGiver | played | 13 Episodes | |
| • David Valcin | played | 11 Episodes | |
| • Clarke Peters | played | 11 Episodes | |
| • Jay O. Sanders | played | 10 Episodes | |
| • Brennan Brown | played | 10 Episodes | |
| • Brett Cullen | played | 9 Episodes | |
| • Camryn Manheim | played | 9 Episodes | |
| • Paige Turco | played | 9 Episodes | |
| • John Doman | played | 8 Episodes | |
| • Michael Kelly (1) | played | 8 Episodes | |
| • Cara Buono | played | 8 Episodes | |
| • Elizabeth Marvel | played | 8 Episodes | |
| • Leslie Odom, Jr. | played | 8 Episodes | |
| • Amy Acker | played | 7 Episodes | |
| • Annie Parisse | played | 7 Episodes | |
| • Anthony Mangano | played | 7 Episodes | |
| • Winston Duke | played | 7 Episodes | |
| • Carrie Preston | played | 6 Episodes | |
| • Sterling K. Brown | played | 6 Episodes | |
| • Wrenn Schmidt | played | 6 Episodes | |
| • Susan Misner | played | 5 Episodes | |
| • Morgan Spector | played | 5 Episodes | |
| • Brian Wiles | played | 5 Episodes | |
| • Sarah Shahi | played | 4 Episodes | |
| • Julian Ovenden | played | 4 Episodes | |
| • John Fiore | played | 4 Episodes | |
| • Ken Leung | played | 4 Episodes | |
| • Jessica Pimentel | played | 4 Episodes | |
| • Jamie Hector | played | 4 Episodes | |
| • Mike McGlone | played | 4 Episodes | |
| • Annie Ilonzeh | played | 4 Episodes | |
| • Kwoade Cross | played | 4 Episodes | |
| • Andreas Damm | played | 4 Episodes | |
| • Cotter Smith | played | 3 Episodes | |
| • Darien Sills-Evans | played | 3 Episodes | |
| • Tuck Milligan | played | 3 Episodes | |
| • Jessica Hecht | played | 3 Episodes | |
| • Mark Margolis | played | 3 Episodes | |
| • Michael Mulheren | played | 3 Episodes | |
| • Allan Louis | played | 3 Episodes | |
| • Brian Hutchison | played | 3 Episodes | |
| • Nick Tarabay | played | 3 Episodes | |
| • Creighton James | played | 3 Episodes | |
| • Luke Kleintank | played | 3 Episodes | |
| • Sean McCarthy | played | 3 Episodes | |
| • Louis Lourens | played | 3 Episodes | |
| • Paul O'Brien (1) | played | 2 Episodes | |
| • Saul Rubinek | played | 2 Episodes | |
| • Joseph Mazzello | played | 2 Episodes | |
| • Bruce Altman | played | 2 Episodes | |
| • Ed Setrakian | played | 2 Episodes | |
| • Damian Young | played | 2 Episodes | |
| • James Hanlon | played | 2 Episodes | |
| • Terry Serpico | played | 2 Episodes | |
| • Laz Alonso | played | 2 Episodes | |
| • Robert Manning, Jr. | played | 2 Episodes | |
| • Jonno Roberts | played | 2 Episodes | |
| • Louis Vanaria | played | 2 Episodes | |
| • Michael J. Burg | played | 2 Episodes | |
| • Diane Davis (1) | played | 2 Episodes | |
| • Luis da Silva, Jr. | played | 2 Episodes | |
| • Faina Vitebsky | played | 2 Episodes | |
| • Michael Stahl-David | played | 2 Episodes | |
| • John Sharian | played | 2 Episodes | |
| • Mike Houston | played | 2 Episodes | |
| • Joseph Melendez | played | 2 Episodes | |
| • Michael Esper | played | 2 Episodes | |
| • Jeanine Serralles | played | 2 Episodes | |
| • Maechi Aharanwa | played | 2 Episodes | |
| • Gregory Lay | played | 2 Episodes | |
| • Quinn Shephard | played | 2 Episodes | |
| • Chris Bert | played | 2 Episodes | |
| • Arash Mokhtar | played | 2 Episodes | |
| • James Knight | played | 2 Episodes | |
| • Gregory Konow | played | 2 Episodes | |
| • Alex Shimizu | played | 2 Episodes | |
| • Logan Crawford | played | 2 Episodes | |
| • Matt Dellapina | played | 2 Episodes | |
| • Daniel K. Isaac | played | 2 Episodes | |
| • Suzy Jane Hunt | played | 2 Episodes | |
| • Adria Arjona | played | 2 Episodes | |
| • Theodora Woolley | played | 2 Episodes | |
| • Oakes Fegley | played | 2 Episodes |