ISD
- Detention (academia)
- Illinois School for the Deaf
- Independence Public School District
- Independent school district
- Indiana School for the Deaf
- Industrial Union of Donbas
- Information Services Department
- Information Services Division
- Institute for Strategic Dialogue
- Instructional systems design
- Integrated Surface Database
- Interboro School District
- Internal Security Department (Brunei)
- Internal Security Department (Singapore)
- International School Dhaka
- International School of Dakar
- International School of Design
- International School of Dongguan
- International School of Düsseldorf
- International Subscriber Dialling
- Issaquah School District
- Team ISD