Number Five's time travel makes his age a bit complicated, but certain details in The Umbrella Academy have made it possible to calculate how old Five really is. The character, played by Aidan Gallagher, serves as one of the super-powered siblings raised by Sir Reginald Hargreeves. Based on the comic book series by Gerard Way and Gabriel Bá, the Netflix series is gearing up for season 3.
As the case with the other Hargreeves siblings, Five was born on October 1, 1989, and raised to form a team of crime-fighters. With the power of jumping through space and time, the young teen had yet to perfect his abilities when he accidentally traveled into the far future. By the time he eventually returned to the present, Five had spent decades working for the Temps Commission as a trained assassin. He returned to his family just in time to save them from the impending Apocalypse caused by his adopted sister, Vanya. In his attempt to protect his siblings, Five subsequently transported them to the 1960s where he discovered yet another world-decimating apocalypse was on the way.
When Five originally jumped to the future, he and his siblings were 13 years old, suggesting that he disappeared sometime during the early 2000s. Had he remained in the primary timeline, Five would have been 30 during the events of The Umbrella Academy season 1 like the rest of his surviving siblings–Luther, Allison, Diego, Klaus, and Vanya. Instead, Five's body reverted back to his young state when he found a way to return to the present, but in reality, he's technically lived the most years as the oldest Hargreeves sibling.
Breaking Down Five's Age In The Umbrella Academy
Upon Five's return to the present, Luther asked how long he was trapped in the future to which Gallagher's character responded with "45 years, give or take." With Five's age at the time of his disappearance and the four and a half decades in the post-apocalyptic period, he was technically around 58 years old in the series. This would make him about 28 years older than his other siblings, which he doesn't let them forget.
In season 2, the ages of each Hargreeves sibling varied a bit since they were scattered throughout different years of the 1960s. This meant that some of them spent varying times in Dallas before reuniting in 1963. In an attempt to get his family back to the present-day, Five encountered a version of himself still working for the Commission. The version, played by Sean Sullivan, served as a more accurate depiction of Five's elder age despite his presence being short-lived.
By the end of The Umbrella Academy season 2, Five managed to successfully get the group back to 2019. The timeline, however, was a different one in which a new academy, called the Sparrow Academy, exists. With Five's time travel abilities, his age might make a few more jumps in upcoming seasons. Seeing as Gallagher continues to age, it's likely that the show will alter Five's appearance at some point. The Umbrella Academy keeps Five in his school-boy uniform as a way to make the actor look younger. With the actor nearing 18, it will only become more difficult to imply that he's still stuck in the body of a 13-year-old.