The Superman prequel series Smallville shows a large portion of the life of Clark Kent before becoming Superman. Smallville first began airing in the fall of 2001, following the story of a teenage Clark Kent (Tom Welling) growing up on a farm in his hometown of Smallville, Kansas. As Smallville progresses, it ventures more into Clark's adult life, with the show's 10th season concluding with Clark fully becoming Superman.
Smallville remains a highly beloved re-telling of Superman's origin story, and Welling's acclaimed portrayal of Clark Kent encompasses an expansive journey of Clark's trials and tribulations as a hero. Due to Smallville's most important rule of "No flights, no tights" until its final episode, the show also centers on a somewhat more youthful depiction of Clark Kent than most adaptations. While Clark's exact age is not revealed on Smallville, the timeline of the show makes it relatively easy to logically infer.
Clark Is Just Starting High School When Smallville Begins
In Smallville's pilot episode, Clark is a freshman at Smallville High School, with Clark having arrived to Earth in his ship from Krypton in 1989. While the infant Clark's age upon his arrival in Smallville is not specified, the fact that he is just at the beginning of high school in the pilot gives major clues to his age. From this, it can be determined that Smallville's future Superman Clark Kent is approximately 14 to 15 years old at the beginning of the show.
Clark's exact birth year is almost impossible to determine, due to the distance between Krypton and Earth and Clark having traveled lightyears to arrive at his new home. Clark could very well have landed on Earth centuries or millennia after Krypton's destruction. This even happened in Superman: The Movie, with Jor-El (Marlon Brando) revealing that he had "been dead for many thousands of your years". Despite this, Clark's age of 14 or 15 at the beginning of Smallville is fairly clear.
How Old Is Clark When Smallville Ends (& His Crisis Cameo)?
When Clark finally dons his red and blue suit to stop Darkseid in Smallville's final episode, 10 years have passed since Smallville began. This would make Clark 24 or 25 years old, but Smallville does not quite end there. In Smallville's final scene, the show makes a time jump to the year 2018, with Smallville's version of Lex Luthor (Michael Rosenbaum) even having becoming President of the United States. This means that, when Clark finally rips open his shirt to reveal the S-shield beneath, he is about 31 to 32 years old.
Tom Welling would return once more as Clark for the CW's DC multiverse mini-series Crisis On Infinite Earths, with Clark having given up his powers and started a family with Lois Lane (Erica Durance). It is harder to say what Clark's age is at this point, though Clark seems to be close to Tom Welling's then-age of 42. With Tom Welling and Michael Rosenbaum hoping to produce an animated continuation of Smallville, Clark's time before giving up his powers could be its basis, or the series could show him with his powers restored. Either way, Smallville has taken Tom Welling's Superman on many years of adventures throughout his arc.