Sayonara Zetsubō Sensei (さよなら 絶望先生, Sayonara Zetsubō Sensei literally Goodbye, Mr. Despair) is a Japanese manga by Kōji Kumeta, serialized in Weekly Shōnen Magazine. It is a comedy about a teacher who takes all aspects of life, language and culture in the most negative light possible.

In 2007, the manga received the thirty-first Kodansha Manga Award in the shōnen category, and was adapted into a twelve-episode anime series. Weekly Shōnen Magazine announced that a second season, titled (Zoku) Sayonara Zetsubō Sensei (【俗・】さよなら絶望先生, (Zoku) Sayonara Zetsubō Sensei literally (Vulgar) Goodbye, Mr. Despair) would be made; it began airing on January 5, 2008.