Superman is known for his incredible speed, but traditionally, he is not depicted as moving faster than light. In most versions of the Superman mythos, his speed is portrayed as being near or slightly surpassing the speed of light, but not exceeding it.
The concept of moving faster than light is usually associated with the concept of the "speed force," which is a fundamental aspect of the DC Comics universe that primarily applies to characters like the Flash. The speed force is a dimension of energy that grants certain individuals superhuman speed and various related abilities.
Superman, however, does not draw his powers from the speed force. Instead, his superhuman speed is a result of his Kryptonian physiology, which grants him enhanced strength, speed, and other abilities due to Earth's lower gravity and its yellow sun. While he can move at incredible speeds, it is generally accepted that he cannot surpass the speed of light without additional abilities or external factors.
That being said, different interpretations and storylines within the Superman comics might present variations on his powers. In certain instances, Superman has been depicted as tapping into other energy sources or utilizing special devices to achieve faster-than-light travel. These depictions, however, are not consistent with the character's traditional portrayal.
It's worth noting that the specifics of Superman's powers can vary across different comic book series, movies, and TV shows. Writers and creative teams often introduce new elements and reinterpretations of his abilities to suit the needs of the story being told.