Mega or MEGA may refer to:

• mega-, the SI prefix for one million (10⁶, symbol M)
• Mega (number)

Mega (stylized in uppercase as MEGA) is a cloud storage and file hosting service produced by Mega Limited. The New Zealand-based website was launched on 19 January 2013 by Kim Dotcom. Mega mobile apps are available for Windows Phone, Android, BlackBerry OS and iOS.

Mega is a town in southern Ethiopia. Located between Moyale and Yabelo on the paved highway south to Kenya, in the Borena Zone of the Oromia Region (or kilil), this town has a latitude and longitude of with an elevation of 1740 meters above sea level. Named for a nearby mountain, this town is the administrative center of Dire woreda.

Mega is a unit prefix in the metric system denoting a factor of one million (10⁶ or ). Symbol (M). It was confirmed for use in the International System of Units (SI) in 1960. Mega comes from the Greek  , meaning "great".