ETA can refer to:

• ETA, a Basque armed organisation.
• eta is a Basque word for "and".
• Eta (letter) - from the Greek alphabet.
• ETA programming language.
• ETA: an acronym for Estimated Time of Arrival.
• Environmental transport association an UK breakdown and rescue organisation.
• An old word for burakumin, who are a minority group in Japan.
• The Estonian Broadcasting Agency (Eesti Teadete Agentuur /ETA/) [1].
• A brand of potato chips made in New Zealand.
• An electrotechnical company from Hlinsko, Czech Republic [2].
• A Swedish hardcore punk band.
• ETA Systems, a defunct manufacturer of supercomputer during the 1980s.
• ETA-10, the line of supercomputers produced by ETA Systems.
• ETA_movement, a brand of mechanical watch movements of the Swatch group
• Eta_reduction, a lambda calculus transformation