Doukyusei (Japanese: 同級生, transl. "classmates"), alternately or dōkyūsei or doukyuusei, may refer to:
- Classmates (manga), a manga series released in Japan as Doukyusei, and its film adaptation Doukyusei: Classmates
- Dōkyūsei (video game series), an eroge video game series
- Dōkyūsei (video game), the first game in the series