What are must watch One Chicago crossover episodes? A list of episodes explored
The One Chicago universe, featuring Chicago Fire, Chicago Med, and Chicago P.D., has created one of the most dynamic and emotionally powerful worlds on television. Each series is compelling on its own, but when they come together for crossovers, the result is unforgettable. These special events highlight the best of One Chicago: thrilling action, heartfelt drama, and the spirit of teamwork across the city’s bravest.
If you're new to One Chicago or looking to relive the biggest moments, this guide walks you through all the major crossover episodes, with a clear breakdown of what happens in each show.
Must-watch One Chicago crossovers (chronological order)
1) Chicago Fire season 1, episode 23: Chicago P.D.'s Backdoor Pilot
Fire Plot: In this One Chicago crossover, Lt. Casey is forced to team up with Voight and the Intelligence Unit for an urgent investigation, while Shay seriously considers becoming a mother. Meanwhile, the crew bonds over the long-awaited grand opening of Molly’s.
2) Chicago Fire season 2, episode 20: A Dark Day
After Chicago P.D. season 1, episode 12: 8:30 PM, this gripping crossover includes a huge explosion in Chicago that compels Firehouse 51 and the Intelligence Unit to collaborate.
While the firefighters attempt rescue operations, the police probe the reason behind the bombing.
3) Law & Order: SVU season 15, episode 15 | Chicago P.D. season 1, episode 6
SVU Plot: After a misogynistic comedian crosses the line with his material, the SVU squad arrests him for sexual assault, though the case proves complicated in court.
P.D. Plot: Fin and Rollins assist Voight’s team in hunting a dangerous serial predator, as Burgess seeks to prove herself and Lindsay reconnects with her past during a high school reunion.
4) Chicago Fire season 3, episode 7 | Law & Order: SVU season 16, episode 7| Chicago P.D. season 2, episode 7
Fire Plot: In this One Chicago crossover, after uncovering disturbing evidence at a fire scene, Severide’s return from Las Vegas with a secret only complicates matters.
SVU Plot: Voight, Lindsay, and Halstead join forces with Benson and her team to dismantle a horrific child pornography ring, but old tensions threaten progress.
P.D. Plot: Together, Intelligence and SVU track the perpetrators, racing against time to protect vulnerable children.
5) Chicago Fire season 3, episode 13 | Chicago P.D. season 2, episode 13
Fire Plot: In this One Chicago crossover, a new lead reignites the investigation into the fire that killed Shay, causing Severide to confront painful memories and old enemies.
P.D. Plot: As Antonio and Lindsay close in on a suspect, Lindsay’s future with the task force becomes increasingly uncertain.
6) Chicago Fire season 3, episode 19: Chicago Med's Backdoor Pilot
Fire Plot: In this One Chicago crossover, Firehouse 51 faces a terrifying ordeal when a patient threatens to unleash a deadly virus, forcing Chicago Med into lockdown and introducing a new generation of doctors.
7) Chicago Fire season 3, episode 21| Chicago P.D. season 2, episode 20 |
Law & Order: SVU season 16, episode 20
Fire Plot: In this One Chicago crossover, after a tragic apartment fire, Dawson risks her life, revealing connections to a gruesome series of crimes.
P.D. Plot: Intelligence collaborates with NYPD’s Benson to connect the dots between the cases, leading to shocking discoveries.
SVU Plot: The chase continues in New York as a kidnapping escalates the urgency of finding the killer.
8) Chicago Fire season 4, episode 10 | Chicago Med season 1, episode 5 |
Chicago P.D. season 3, episode 10
Fire Plot: In this One Chicago crossover, Firehouse 51 rallies after a team member suffers a life-threatening injury, while Cruz searches for a missing friend.
Med Plot: The team at Med faces difficult ethical choices when a mystery patient arrives, linking to a broader conspiracy.
P.D. Plot: Intelligence investigates a doctor tied to suspicious deaths, putting their trust in the system — and each other — to the test.
9) Law & Order: SVU season 17, episode 14 | Chicago P.D. season 3, episode 14
SVU Plot: Detectives track escaped killers across state lines, enlisting help from Chicago’s finest.
P.D. Plot: In this One Chicago crossover, the manhunt for Gregory Yates takes a dark turn when more bodies are discovered in Chicago.
10) Chicago Fire season 5, episode 9 | Chicago P.D. Season 4, Episode 9
Fire Plot: In this One Chicago crossover, as Severide wrestles with a personal crisis, Dawson and Casey fight to keep custody of Louie amid legal challenges.
P.D. Plot: Severide becomes entangled in a deadly car accident investigation, straining his relationship with the department.
11) Chicago P.D. season 5, episode 16 | Chicago Fire season 6, episode 13
P.D. Plot: A string of bombings against media outlets leads Intelligence to seek help from Firehouse 51 in dismantling deadly devices.
Fire Plot: Brett and Dawson go undercover on Voight’s orders, while personal relationships at Firehouse 51 come under strain.
12) Chicago Fire season 7, episode 2 | Chicago Med season 4, episode 2 |
Chicago P.D. season 6, episode 2
Fire Plot: Firehouse 51 confronts a catastrophic high-rise blaze, with personal stakes rising when the Halstead brothers' father goes missing.
Med Plot: Chicago Med faces a flood of injured victims, forcing doctors to make split-second life-and-death decisions.
P.D. Plot: As Intelligence investigates the cause of the fire, they uncover a calculated act of arson.
13) Chicago Fire season 7, episode 15 | Chicago P.D. season 6, episode 15
Fire Plot: When a lockbox key goes missing during a series of burglaries, Cruz goes undercover, risking trust with his department.
P.D. Plot: Voight’s unit follows leads into a deeper criminal conspiracy — one that could involve CFD itself.
14) Infection: Part I | Infection: Part II | Infection: Part III
Fire Plot: Chicago Fire season 8, episode 4, A mysterious bacterial infection sparks widespread panic across the city, pulling in Firehouse 51.
Med Plot: Chicago Med season 5, episode 4, Chicago Med races to treat and contain the outbreak, while tensions flare among the hospital staff.
P.D. Plot: Chicago P.D. season 7, episode 4, Intelligence tracks the bioterrorist responsible, culminating in one of their most critical missions yet.
15) Chicago Fire season 8, episode 15 | Chicago P.D. season 7, episode 15
Fire Plot: Severide teams up with retired officer Sean Roman to investigate a series of teenage overdoses, revealing painful secrets.
P.D. Plot: The Intelligence Unit digs deeper into Chicago’s opioid epidemic, leading to tragic and chilling discoveries.
16) Chicago Fire season 13, episode 11 |Chicago Med season 10, episode 11 | Chicago P.D. season 12, episode 11
Fire Plot: A massive explosion at a city building thrusts Firehouse 51 into a race against time, coordinating rescues underground.
Med Plot: Amid the tunnel collapse, emergency surgery and triage efforts test the limits of Chicago Med's team.
P.D. Plot: As conditions deteriorate underground, Intelligence works fast to find those responsible for the catastrophe.
From action-packed rescues to suspenseful investigations and gut-wrenching medical cases, One Chicago crossovers are more than great TV—they're a tribute to unity, loyalty, and courage throughout the Windy City.
Watch Chicago Fire, Chicago P.D., and Chicago Med streaming on Peacock.
