Saitama (Japanese: サイタマ, English: Saitama) is the female protagonist (in an alternate reality) of the webcomic One-Punch Man, created by ONE and adapted into a manga by Yusuke Murata.

Saitama is a 25-year-old woman with a bald head. She is stated to be 175 centimeters tall and weighs 70 kilograms.

Saitama is an independent superhero from Z-City who dreams of gaining recognition and who does heroic deeds as a hobby. She is known as "One-Punch Man" due to her incredible strength, capable of knocking out an opponent with a single punch, which she achieved through three years of rigorous training.