Tom Welling's Clark Kent may have been perfect for Smallville, but he can't ever play Superman. Smallville enjoyed a 10-season run and remains a firm fan favorite even a decade after its final season. Its star, Tom Welling, brought a new version of young Clark Kent to life, and the show explored his origins as a Kansas farm boy as he set out on the path toward becoming a hero.
One of Smallville's cardinal rules was "no tights, no flights" - a mandate created by the show's creators, Alfred Gough and Miles Millar. The idea behind it was that despite Smallville being the perfect Superman origin story, it was important to keep it as strictly that, with Clark Kent not becoming the iconic hero until the final episode. The rule might seem risky - not including any of the most recognizable aspects of its main character is an interesting choice - but ultimately, it paid off, and Smallville remains an important and beloved part of Superman's wider canon.
Despite Welling starring as Clark Kent for a full decade, the actor has never actively portrayed Superman, and it's unlikely that he ever truly will in live-action. With his role on Smallville becoming such a thorough exploration of Clark Kent and the show's "no tights, no flights" rule being such an integral part of it, it's simply not something that Welling's quite right for. Outside of voicing Superman in Smallville's animated spin-off, he'll likely never play the Man of Steel, and there's a number of reasons why.
The DCEU And Arrowverse Already Have Their Supermen
DC's continuity is currently somewhat convoluted, with two major separate universes, as well as a number of cinematic offshoots, presently occurring. While this in and of itself isn't a major issue, it is one of the most obvious reasons why Tom Welling cannot assume the mantle of Superman. There are already multiple incarnations of the character existing in live-action, specifically Henry Cavill's DCEU version and Tyler Hoechlin's Arrowverse iteration.
While the future of Henry Cavill's Superman is currently unknown, there's been no indication that the DCEU will be recasting the role. Hoechlin's Superman is fast becoming a fixture of the Arrowverse, simultaneously establishing big differences between Superman & Lois and Smallville. With two existing Supermen in current DC continuity, there's simply no space for Welling to resume the role without further confusing matters.
There Have Been Other Superman Actors Since Smallville
As well as Hoechlin and Cavill, there have also been other Supermen since Smallville began. Most notably, there was Superman Returns' Brandon Routh, who took up the role for the 2006 continuation of Christopher Reeve's cinematic arc. Routh took to the skies five whole years after Welling began portraying Clark Kent, further separating Welling from the role of Superman.
While Welling might be set to voice Clark Kent/Superman in the animated Smallville spin-off, there have been other Superman voice actors since, too. John Krasinski is voicing the character in DC League of Super-Pets, meaning that even in animation, Welling will have considerable competition. Although fans are keen to know what happened to Tom Welling's Superman after Smallville ended, seeing him as Superman just won't carry the weight it once would have.
Welling's Clark Kent Was Unique
One of the things that made Tom Welling's Clark Kent so popular was the unique spin Smallville put on the character. By taking such time and care with exploring his origins, Smallville actually transformed its Clark into a much more interesting and rounded character than he's often depicted as within other media. More often than not, Clark is treated as Superman's disguise, whereas Smallville built its story around the opposite - Clark hiding the secret of his true nature from his friends and family while learning to be a hero.
As well as original characters and new colors of Kryptonite, Smallville also introduced an incredibly robust way of examining Clark's teenage years. This actually makes Smallville's eventual Superman a very different character to other incarnations, particularly as so many of its other heroes and villains have much greater insight into all aspects of Clark's life. Having played such a unique take on Clark Kent, Tom Welling as Superman could potentially be a hard sell, particularly after the significant changes Smallville made to Superman's wider canon.
Welling Is Getting Too Old To Play Superman
Smallville ran for ten years, and it's been even longer since it ended. This makes Tom Welling over two decades older than he was when he first took on the role, and perhaps too old to pick up back up in any substantial way. While the specifics of Superman/Clark Kent's age is hardly ever an issue for fans, the idea of an older Superman presents a particular barrier exclusive to Tom Welling.
As Welling's biggest and most iconic role was that of Clark Kent before he became Superman, to have him actually step into the role after two decades would be bittersweet. While most Smallville fans would have no issue with seeing Welling don the cape and tights, it would be all too obvious that he was effectively robbed of his chance at the role in a more substantial sense. After all, Welling's turn as the character ended just as he came into the perfect age to play Superman, and he's now at the tail end of that window. Welling's age doesn't make it an impossibility that he could be the next actor to play Superman in live-action, especially as the DCEU leans towards older Batman actors, but it does make it seem much less likely.
Why Welling Won't Play Superman
For many years, it seemed to be something of a certainty that Tom Welling would one day become Superman. After ten seasons of build-up, Smallville rightly opted not to show its protagonist as the hero, and instead kept Welling's role as that of Clark Kent and not his iconic alter-ego. However, as Tom Welling has since been passed over for the role on numerous occasions, it now seems all but impossible for him to ever become Superman.
While Welling was Smallville's perfect Clark Kent, the show's decision to distance itself from more direct portrayals of Superman and his powers ultimately proved a double-edged sword. It may have been a key factor in determining the show's overall success, but it also forced a degree of separation between Welling and the role he seemed destined to play. Over ten years on from Smallville's end, it appears that Tom Welling will never become Superman, even if he was the perfect Clark Kent.