CAIS
- CAI (disambiguation)
- Cais (surname)
- Calcium–aluminium-rich inclusion
- Canadian Academy of Independent Scholars
- Canadian Accredited Independent Schools
- Canadian Association for Information Science
- Canadian Association for Irish Studies
- Center for AI Safety
- Central American Integration System
- Changchun American International School
- Chemical Agent Identification Set
- Chinese American International School
- Christian Alliance International School
- Complete androgen insensitivity syndrome
- Erol's Internet
- Paul Gray (information technology)