Geki is Japanese for "strike" and may refer to:
- Geki (driver) (1937–1967), pseudonym of Giacomo Russo, an Italian race car driver
- Juken Sentai Gekiranger, a Japanese television program
- Geki, a fictional ninja in Street Fighter arcade games
- Geki/Tyranno Ranger, a fictional character in Kyōryū Sentai Zyuranger tokusatsu television series
- Bear Geki, a character in Saint Seiya