Jesse Spencer's Chicago Fire exit and returns explained: Why he left and what brought him back

From the very beginning, Jesse Spencer has always been a key figure within the One Chicago fandom thanks to his starring role as 51 lieutenant turned captain Matt Casey. Across the first ten seasons of the show, Casey was a key character on Chicago Fire and was often at the forefront of some of the show’s biggest storylines. 

Honestly, it’s fair to say that Chicago Fire might not have ever evolved into the show it has become today without Spencer and his character as he and Taylor Kinney were the faces of the franchise for many years and their characters were the biggest draws for the millions of fans tuning in weekly. 

Casey was such an important part of the show, and fans were shocked when he announced his departure in season 10. Fortunately, he hasn’t been able to stay away from the show which has led to quite a unique journey for his character and his fans. While many actors who have left the franchise, have never returned after their exit, Casey’s storyline only continued to evolve after his absence with several major milestones happening after Spencer left the show as a series regular. 

Why did Jesse Spencer leave Chicago Fire? 

Let’s start at the beginning by exploring Jesse Spencer’s exit from the show. In the series, Casey left 51 in order to move to Oregon to take care of his former 51 colleague and friend Andrew Darden's sons, becoming their legal guardian. This exit storyline left the door open for Casey to return to the show, which he’s done several times since Spencer’s departure. 

Spencer’s last official episode as a series regular on the show came in Chicago Fire’s 200th episode, “Two Hundred,” in which Casey made the decision to leave Chicago in order to take care of the Darden boys upon learning that the siblings were in jeopardy of being split up via the foster care system. The episode explained Casey’s exit away in a clear manner, but the reason the storyline was introduced is because of Spencer’s desire to take a step back from the series after 10 years on the show. 

As he told People following his exit, "This was a difficult decision because I have loved the show from the start but there are other things that I would like to do in the future, and there's some family that I need to take care of. I was marking off these milestones and looking to the future … and it was time."

Fortunately, Spencer left on good terms and while “Two Hundred” might have been his final episode as a series regular, he’s returned several times since exiting the show early in season 10. 

Breaking down when Casey returns to Chicago Fire

Thus far, Jesse Spencer has returned for four episodes since his original exit as a series regular on Chicago Fire, returning in the season 10 finale, two episodes in season 11, and one episode in season 12. It’s unclear whether we might see Spencer return in the show’s upcoming season, but the door is open so we can’t rule out an exit. 

Spencer first returned in the season 10 finale, “The Magnificent City of Chicago,” in which his character returned for the wedding of Severide and Kidd. It was a return that many fans hopped might happen as it felt wrong for Casey not to be present at the wedding of his longtime friend, and fortunately, Spencer agreed to return for the episode which saw Casey coming back to town to partake in the wedding festivities and enjoy a sweet, though bittersweet reunion with Brett in which the pair seemed to come to an agreement that long distance wasn’t working out as well as they hoped. 

Spencer next returned in season 11, episode 18, “Danger Is All Around,” returning to work alongside Kidd as part of a special task force investigating and we discover that he’s still hung up on Brett, hinting at a possible reconciliation between the couple. 

Said reconciliation came in the season 11 finale, “Red Waterfall,” when Casey returned to Chicago once again this time with the intention of professing his love to Brett by getting down on one knee and asking her to marry him. This moment seemed to hint that he could perhaps return again in season 12 and that was indeed the case – though Spencer’s return came a bit later than fans expected. 

While we learned in the season 12 premiere that Brett said yes to his proposal, Casey didn't return until later in the season. Spencer last returned to Chicago Fire in season 12, episode 6, “Port in the Storm,” which served as the final episode for Kara Killmer’s Brett. The show tied Brett’s exit storyline into a happy ending for her and Casey as their wedding day arrived and with it came Spencer’s return as Casey. In the episode, we got to see Casey and Brett exchange I Do’s before the couple left Chicago together to head back to Oregon to live together with their family. 

Given that Casey and Brett are still alive and well in the One Chicago universe, there is always a chance that we could see Spencer returning as Casey again in future seasons but at the present moment there have been no rumors about a possible return. Still, the show has surprised us before and we’ve yet to have a season without an appearance from Spencer in at least one episode so it’s possible we could see him return in season 13 for a guest appearance or two!