SAI is an acronym for :

• Safety Appliance Illustration
• Sailfish (FAO fish species code)
• Sea-to-Air Interface
• Secretariat al'Adoption Internationale
• Security Awareness Index
• Semi-Automatic Interface
• Senior Army Instructor
• Serving Area Interface
• Sigma Alpha Iota (women's music fraternity)
• Simplified Ab Initio Method
• Sistema de Alimentacion Ininterrumpida (Spanish: uninterruptible power supply)
• Social Accountability International
• South African Infantry (South African ground troops in World War I)
• South American Indian (language)
• Spanish Artificial Intelligence
• Specific Area of Interest
• Sports Authority of India
• Standard Advertising Invoice
• Standards Australia International Ltd.
• Standby Attitude Indicator
• Statement of Additional Information (SEC)
• Steering Axis Inclination
• Strategic Command Administrative Instruction (USSTRATCOM)
• Structural Adequacy Index (pavement assessment)
• Sua Altezza Imperiale (Italian: His/Her Imperial Highness; codices and manuscripts)
• Supreme Audit Institution (Republic of Korea)
• Surveillance-Aided Intercept
• Sweet Adelines International (International Organization of Women Barbershop Singers)
• Systems Application Integration
• Systems Architecture and Interfaces (Aeronautical Radio Incorporated)