DSI
- Apple Filing Protocol
- DSI Samson Group
- Daiichi Sankyo
- Dance Club Songs
- Data Storage Institute
- Data Stream Interface
- Dave Smith Instruments
- Dead Space Ignition
- Decision Sciences Institute
- Deep Space Industries
- Deep Springs International
- Delay slot
- Delphi Schools
- Delphine Software International
- Department of Special Investigation
- Depolarization-induced suppression of inhibition
- Destin Executive Airport
- Destination Software
- Detective Superintendent
- Deutsche Schule Istanbul
- Dienst Speciale Interventies
- Digital Serial Interface
- Digital sequence information
- Display Serial Interface
- Distinctive Software
- Diversified Specialty Institute Holdings, Inc.
- Diverterless supersonic inlet
- DontStayIn
- Dope Stars Inc.
- Drivetrain Systems International
- Nintendo DSi
- SOFIA
- Special Intervention Detachment
- State Hydraulic Works (Turkey)
- Stuttgart Database of Scientific Illustrators 1450–1950