| Abbreviation | Definition |
|---|---|
| ISAL | International School of Advanced Learning |
| ISAP | In School Adjustment Program |
| ISAP | In School Alternative Program |
| ISAP | Interim School Administrator Program |
| ISARS | International School of Advanced Research Study |
| ISAS | Independent Schools Association of the Southwest |
| ISB | International School Brunei |
| ISB | International School of Beaverton |
| ISB | International School of Beijing |
| ISB | International School of Bejing |
| ISB | International School of Belgrade |
| ISB | International School of Boston |
| ISB | International School of Brooklyn |
| ISB | International School of Broward |
| ISBC | Independent Schools Benefits Consortium |
| ISBC | International School on Biological Crystallization |
| ISBD | International School of Biomedical Diagnostics |
| ISBF | Indian School of Business Finance |
| ISBG | Idaho School Bond Guaranty |
| ISBI | Independent Schools of the British Isles |