Gen may refer to:
- Gen (film), 2006 Turkish horror film directed by Togan Gökbakar
- Gen (Street Fighter), a video game character from the Street Fighter series
- Gen Fu, a video game character from the Dead or Alive series
- Gen language, the language of Togo
- Gen-san, a character in the anime series Sky Girls
- Gen Tomii (富井 彦, born 1973), Japanese Nordic combined skier
- Gen Hoshino (星野 源, born 1981), Japanese singer-songwriter, musician, actor, and writer
- Gen Shoji (昌子 源, born 1992), Japanese footballer
- Gen Urobuchi (虚淵 玄, born 1972), Japanese novelist, visual novel writer and anime screenwriter
- Gen Fukunaga (福永 元, born 1962), Japanese engineer and businessman
- Gen Nakatani (中谷 元, born 1957), Japanese politician
- Gen Horiuchi (堀内 元), Japanese ballet dancer and choreographer
Gen. or GEN may refer to:
- General officer, a high senior rank in the military
- GEN Corporation, of Japan
- GEN Energija, a state-owned power company in Slovenia
- GEN, a website published by Medium
- Global Ecovillage Network
- Global Editors Network
- Gewestelijk ExpresNet, Dutch name for the Brussels Regional Express Network, a commuter rail service
- Genitive case