Giga- is a prefix for one billion.

Giga or GIGA may also refer to:

• Gigue or giga: a Baroque dance
• Ģīga, a Latvian musical instrument
• Giga (instrument), a Scandinavian musical instrument

• Giga (given name), a Georgian given name
• Giga (brand), an adult game and visual novel brand
• Giga Pets, a series of virtual pets
• GIGA Television, a German TV station
• German Institute for Global and Area Studies
• Giga (United Nations), UN projects, e.g. to connect schools to the internet
• Isuzu Giga, truck series
• St.GIGA, a Japanese satellite radio station
• Ivan Vuković, or Giga, Montenegrin footballer

• Gega (disambiguation)