Tengiz, Teniz (Kazakh: Теңіз; Russian: Тениз), or Tengis is a Turco-Mongol word meaning sea.

It may refer to:

• Tengiz Lake, a lake in Akmola Region, Kazakhstan
• Tengizi Islands, an island chain sited within Lake Tengiz
• Tengiz Field, an oil field in Atyrau Region, Kazakhstan
• Teniz, Kamysty District, a lake in Kostanay Region, Kazakhstan
• Teniz, Mendykara District, a lake in Kostanay Region, Kazakhstan
• Teniz, Yereymentau District, a lake in Akmola Region, Kazakhstan
• Tengis River, a river in Mongolia
• Tengiz (given name), a Georgian given name

• Tenis