Gau may refer to:

• Gau, a Cantonese vulgar word
• GAU, the University of Göttingen (German: Georg-August-Universität Göttingen)
• Gau (country subdivision), German term for a shire (regional administration)
• Gau (grape), another name for the French wine grape Gouais blanc
• Gau, a character in Final Fantasy VI
• Gau Meguro, a character in the manga Nabari no Ou
• Gau Island, an island in Fiji
• Gau Mata, a sacred cow in Hinduism
• General Assistance Unemployable a Washington State unemployment program
• Lokpriya Gopinath Bordoloi International Airport in Guwahati, Assam, India (IATA code GAU)
• Saint Gaugericus (Gau, Géry)
• Gäu District, district of Solothurn, Switzerland
• Girne American University, a university in Northern Cyprus
• Gun, aircraft unit, a series of US aircraft guns:
  • Minigun, also known as GAU-2/a or GAU-17/A
  • M61 Vulcan, also known as GAU-4/A
  • GAU-7 cannon
  • GAU-8 Avenger
  • M2 Browning machine gun, different versions known as GAU-10/A, GAU-15/A, GAU-16/A, GAU-18/A or GAU-21/A
  • GAU-12 Equalizer
  • GAU-13
  • GAU-19
• GAU, Größter Anzunehmender Unfall, German term used for nuclear accidents at approximately level 4 on the International Nuclear Event Scale
  • Super-GAU, term applied to the most serious accidents, such as the Chernobyl disaster

A panhole is a depressed, erosional feature found on flat or gently sloping rock. Panholes are the result of long-term weathering and are generally seen on bedrock or very large blocks of rock. Similar terms are gnamma (Australia), opferkessel (German, roughly “sacrificial basin”), “armchair hollows”, weathering pans (or pits) and solution pans (or pits). Other German names include kamenitza and kamenica. In Spanish they are tinajita.