United States Department of Justice

Alcohol, Tobacco, Firearms & Explosives Bureau

 * Supervisory Special Agent - Geg Hammet, Group Supervisor - (Chicago PD S4 E15)
 * Supervisory Special Agent - Jim Anderoff, Group Supervisor - (Chicago PD S2 E12)
 * Special Agent - _____ Sanchez, (FBI S4 E9)
 * Special Agent - Stephen Troy, (FBI S1 E8 & S4 E9)
 * Special Agent - Eric Collins, (Chicago PD S2 E6)

U.S Drug Enforcement Administration

 * Known Field Office;
 * Chattanooga Field Office:
 * Special Agent - Clayton Smith, (FBI: Most Wanted S2 E15)
 * Philadelphia Field Office:
 * Special Agent - Greg Galson, (FBI: Most Wanted S3 E12)
 * New York Field Office:
 * Special Agent in Charge - Tom Brennan, (FBI S2 E5)
 * Chicago Field Office:
 * Special Agent - Thomas ______, (CPD S5 E10)
 * Special Agent - Freddie Castillo, (Chicago PD S2 E11 - E12)
 * Special Agent - David Lang, (Chicago PD S2 E9 - S2 E11)
 * External Links:
 * S.A - Freddie Castillo, https://one-chicago-fbi.fandom.com/wiki/Freddie_Castillo
 * S.A - David Lang, https://one-chicago-fbi.fandom.com/wiki/David_Lang

Federal Bureau of Investigations

 * Assistant Special Agent In Charge - Raoul Toscana, (FBI: MW S1 E11)
 * Assistant Special Agent In Charge - Joe Franklin, (FBI S1 E11)
 * Special Agent in Charge - Rashad Alero, (FBI: MW S2 E3 and S3 E2)
 * Special Agent - William Hopper, (FBI S1 E20)
 * Special Agent - Jane Cisneros, (FBI S2 E7)
 * Special Agent - ____ Foster, (Chicago Med S7 E9 - ?)
 * Special Agent - Marty Bowen, (FBI S4 E11)
 * Special Agent - ____ Russo, (Chicago Med S7 E9 - ?)
 * Special Agent - ____ Zayas, (FBI: Most Wanted S1 E9)
 * Special Agent - ____ Keller, (Chicago PD S5 E10)
 * Special Agent - ____ Shen, (FBI S1 E18)
 * Special Agent - Nina Chase, (FBI S4 E17)
 * Special Agent - ____ Holt, (FBI S1 E20)
 * Special Agent - Dan Small,  (FBI: MW S2 E5)
 * Joint Terrorism Task Force: Special Agent - Lisa Moss, (FBI: MW S2 E14)

U.S Office of Attorney General

 * Chief Law Enforcement Officer: Attorney General - Rebecca Blair, (FBI: International S1 E14)
 * Security Detail: FBI Special Agent - Kyle Harmon, (FBI: International S1 E14)
 * Senior Administrative Aide - Kenneth Gregory, (FBI: International S1 E14)
 * ______ Unit Chief - ______ _. Grimes,  (FBI: International S1 E14)

U.S Marshals Service

 * US Chief Deputy Marshal - Paul Acherman, (FBI S1 E9)
 * US Deputy Marshal - Tara McPherson, (FBI: Most Wanted S3 E12)
 * US Marshal - _____ Samuels, (FBI: Most Wanted S3 E12)
 * US Marshal - Carter Larsen, (FBI: Most Wanted S2 E3)