Which Halstead Brother In One Chicago Is Older?

In the world of TV siblings, "One Chicago" regulars Dr. Will Halstead (Nick Gehlfuss) of "Chicago Med" and Detective Jay Halstead of "Chicago P.D." (Jesse Lee Soffer) have developed into one of the small screen's most popular brother acts. First seen together in 2017 when Jay crossed over to join Will in the appropriately titled "Chicago Med" Season 2 episode "Generation Gap" (per IMDb), their dynamic has been, well, complicated from the start.

For one thing, Jay has always low-key resented Will for how the latter, in Jay's opinion, left Jay home with their ailing mother and domineering father. Feeling that Will was simply off partying while he cared for their mom as she died from cancer, Jay seems to think Will is too impulsive and nonchalant to be considered a responsible adult. For his part, Will basically thinks Jay goes "by the book" a little too often, and he also carries a bit of guilt about his past behavior with Jay and their family and can be defensive as a result. But, while the two may sometimes clash due to their history, they both nonetheless always support each other and come to one another's defense whenever needed. So, with this somewhat emotion-charged backstory to consider, which of the "One Chicago" Halstead brothers would you guess is the older sibling?

In the Chicago-verse as it currently exits, Will Halstead is inarguably older than Jay. This fact was conclusively established in a 2020 Twitter exchange that began when fan @cardiganswillow posted this plea: "one chicago stan twitter has the same discussion about who the older halstead brother is every month help." No less an authority than Jesse Lee Soffer himself responded, answering: "Will is older on tv. Jesse is older in real life."

And while this definitive tweet would seem to settle the issue, it's interesting to note that the age hierarchy of the Halstead bros has taken a while to become canon. As spotted by Redditor u/ell_fin, "When he was introduced in PD jay does refer to him [Will] as his little brother, but in Med he is referred to as the older brother so yeah, plot holes." And, as One Chicago Center proposes, it seems likely that the series' execs simply made the decision to make Will the big brother of the two because "it made more sense for Will to be the older brother instead of Jay (even if their personalities suggest otherwise)." The site added that it doesn't sound like much of a stretch to flip them, considering how close Soffer and Nick Gehlfuss are in terms of real-life age.