Main cast •
Jesse Spencer as Lieutenant Matthew Casey, Truck 81 •
Taylor Kinney as Lieutenant Kelly Severide, Squad 3 •
Monica Raymund as Paramedic in Charge/Firefighter Candidate Gabriela Dawson, Ambulance 61/Truck 81 •
Charlie Barnett as Firefighter/Paramedic in Charge Peter Mills, Squad 3/Ambulance 61 •
Kara Killmer as Paramedic Sylvie Brett, Ambulance 61 •
David Eigenberg as Firefighter Christopher Herrmann, Truck 81 •
Yuri Sardarov as Firefighter Brian "Otis" Zvonecek, Truck 81 •
Joe Minoso as Firefighter Joe Cruz, Truck 81/Squad 3 •
Christian Stolte as Firefighter Randy "Mouch" McHolland, Truck 81 •
Eamonn Walker as Chief Wallace Boden, Battalion 25
Recurring • Randy Flagler as Firefighter Harold Capp, Rescue Squad 3 • Anthony Ferraris as Firefighter Tony, Rescue Squad 3 •
Edwin Hodge as Firefighter Rick Newhouse, Rescue Squad 3 •
Melissa Ponzio as Donna Robbins-Boden •
Warren Christie as Firefighter Scott Rice, Rescue Squad 3 •
Gordon Clapp as Chaplain Orlovsky •
Kenny Johnson as Lieutenant Tommy Welch, Truck 66/Firefighter, Rescue Squad 3 •
Eric Mabius as Jack Nesbitt •
Yaya DaCosta as April Sexton •
Izabella Miko as Katya •
Richard Roundtree as Wallace Boden, Sr. •
Serinda Swan as Brittany Baker •
Lauren German as Leslie Shay •
Dora Madison as Paramedic in Charge, Jessica "Chili" Chilton, Ambulance 61 •
James Russo as Papa Lullo • Alexandra Metz as Elise Mills •
Joe Keery as Emmett
Crossover characters •
Amy Morton as Sergeant Trudy Platt •
Brian Geraghty as Officer Sean Roman •
Jon Seda as Detective Antonio Dawson •
Jason Beghe as Sergeant Henry "Hank" Voight •
Marina Squerciati as Officer Kim Burgess •
Jesse Lee Soffer as Detective Jay Halstead •
Nick Gehlfuss as Dr. Will Halstead •
Sophia Bush as Detective Erin Lindsay •
Patrick John Flueger as Officer Adam Ruzek •
LaRoyce Hawkins as Officer Kevin Atwater • Samuel Hunt as Greg "Mouse" Gerwitz •
Kelli Giddish as Detective
Amanda Rollins •
Mariska Hargitay as Sergeant
Olivia Benson •
Tamara Tunie as
M.E. Melinda Warner ==Episodes==