Superman is essentially immortal and can live indefinitely, as long he avoids Kryptonite radiation, which is the only thing known to be able to kill him. In the comic book universe, Superman’s longevity isn’t explicitly stated, but he often appears to travel through time, which reinforces his status as an ageless being.
Based on the evidence from the comic books and other media, it appears that Superman can indeed live forever in theory.
In 1983’s Superman Returns, a film released by Warner Bros., the audience discovers that Superman is seemingly “alive” thousands of years in the past. This could mean that Superman can essentially go on living for eternity, as long as he is able to steer clear of any dangers which could end his life.
Some have also theorized that Superman may be able to regenerate himself through solar energy, as solar rays are a source of power and life for him.
All in all, it’s impossible to know exactly how long Superman can live, as it’s open to interpretation. But the evidence suggests he could live forever, so long as he avoids anything that may end his life.
