SAIS or Sais can refer to:

• Paul H. Nitze School of Advanced International Studies, part of The Johns Hopkins University
• Sharjah American International School
• Southern Association of Independent Schools
• Sportscotland Avalanche Information Service
• Stamford American International School, located in Singapore
• Strange Adventures in Infinite Space, a 2002 computer game

Sais or Sa el-Hagar was an ancient Egyptian town in the Western Nile Delta on the Canopic branch of the Nile. It was the provincial capital of Sap-Meh, the fifth nome of Lower Egypt and became the seat of power during the Twenty-fourth dynasty of Egypt (c. 732–720 BC) and the Saite Twenty-sixth dynasty of Egypt (664–525 BC) during the Late Period. Its Ancient Egyptian name was Zau.