| ISPP | Illinois State Physics Project 
| Others |
| ISPP | In situ propellant production
| Others |
| ISPP | Individualized Supervised Practice Pathway
| Others |
| ISPP | Individualized Supervised Practice Pathways
| Others |
| ISPP | Individualized Supervised Practice Program
| Others |
| ISPP | Innovation Society and Public Policy
| Others |
| ISPP | International School of Phnom Penh
| Others |
| ISPP | International Sewage Pollution Prevention
| Others |
| ISPP | International Society for Plant Pathology
| Others |
| ISPP | International Society for Psychoanalysis and Philosophy
| Others |
| ISPP | International Society of Plant Pathology
| Others |
| ISPP | International Society of Political Psychology
| Others |
| ISPP | International Society of Proprioception and Posture
| Others |
| ISPP | International Society of Psychoanalysis and Philosophy
| Others |
| ISPP | International Study of the Preparation of Principals
| Others |
| ISPP | International Symposium on Pediatric Pain
| Others |
| ISPP | International Symposium on Phototrophic Prokaryotes
| Others |
| ISPP | International Symposium on Plant Photobiology
| Others |
| ISPP | Irish Sea Portal Pilot
| Others |