Kasumi (Japanese: かすみ, also written as 霞, meaning "mist" or "afterglow") is a fictional character and the protagonist of the Dead or Alive fighting game series by Team Ninja and Tecmo (Koei Tecmo). Kasumi has served as the lead character of the Dead or Alive franchise since its premiere in 1996. She was a main character in the first, second and fifth games of the series and in the film DOA: Dead or Alive.

In the games' canon, Kasumi, also known as "The Kunoichi of Destiny", is a teenage ninja princess of the Mugen Tenshin Ninja Clan. Kasumi abandoned her clan, becoming an outcast and is pursued by her younger half-sister Ayane. There are several Dead or Alive player and boss characters who are clones of her. She also guest appeared in various other games, including Team Ninja's other flagship series Ninja Gaiden where she and Ayane play much bigger roles.

Kasumi has become a symbol of the Dead or Alive franchise and is the personal favourite of Team Ninja's founder and the series' creator Tomonobu Itagaki. She has been the subject of various merchandise and was used to promote the Xbox consoles in Japan. Kasumi is a popular sex symbol in video game culture and an iconic ninja character. Due to differences in cultural norms, she has attracted some controversy in the West involving eroticism and the use of underage female characters in video games.