| Acronym | Definition |
|---|
| ISP | Internet Service Provider (most common) |
| ISP | International Security Program |
| ISP | Institut Scientifique de Santé Publique (Belgium) |
| ISP | Illinois State Police |
| ISP | Indiana State Police |
| ISP | Idaho State Police |
| ISP | Information Service Provider |
| ISP | Independent Solutions Provider |
| ISP | International Security Policy |
| ISP | Individual Service Plan |
| ISP | International Specialty Products |
| ISP | In-System Programmable |
| ISP | Specific Impulse |
| ISP | Instituto de Salud Publica (Chile equivalent to US FDA) |
| ISP | Internet Solution Provider |
| ISP | Independent Study Program |
| ISP | International Studies and Programs |
| ISP | Institute of Sales Promotion |
| ISP | Independent Study Project |
| ISP | Interface Segregation Principle |
| ISP | International Standardized Profile |
| ISP | In-System Programmability |
| ISP | Information Security and Privacy (International Conference) |
| ISP | International Settlements Policy |
| ISP | Inside Plant (telephone) |
| ISP | Image Signal Processor |
| ISP | Independent Service Provider |
| ISP | Information Systems Professional (Canadian Information Processing Society) |
| ISP | Instruction Set Processor |
| ISP | Infrastructure Service Provider |
| ISP | Institut Supérieur Pédagogique (French) |
| ISP | Intensive Supervision Probation |
| ISP | Institute of Store Planners |
| ISP | Invisibl Skratch Piklz (scratch DJs) |
| ISP | Intelligent Signal Processing |
| ISP | Integrated Support Plan |
| ISP | Information Systems Plan |
| ISP | Information Support Plan (US DoD) |
| ISP | Information Sharing Protocol (NASA TCP/IP protocol used to distribute telemetry) |
| ISP | Information Strategy Plan |
| ISP | Interrupt Status Port |
| ISP | Industry Specialization Program (IRS) |
| ISP | Integrating Sphere (optical engineering) |
| ISP | Income Security Program (Canada) |
| ISP | Intensive Supervised Probation (form of probation in corrections/criminal justice) |
| ISP | Incorporated Society of Planters |
| ISP | Incentive Special Pay (US DoD) |
| ISP | Indigenous Sport Program (Australia) |
| ISP | In Store Processor |
| ISP | Initial Science Plan |
| ISP | Image Synthesis Processor |
| ISP | Israel Seed Partners |
| ISP | Implementation Support Plan |
| ISP | Information Strategic Plan |
| ISP | Institute for Shock Physics (Washington State University) |
| ISP | Integrated System Peripheral |
| ISP | Institutional Strategy Paper |
| ISP | International Society of Photogrammetry |
| ISP | Incentive Savings Plan |
| ISP | Integrated Survey Program |
| ISP | Intelligence Support Plan |
| ISP | Initial Science Program (IAI) |
| ISP | International Service Program |
| ISP | Intermediate Service Part |
| ISP | Inscribed Signed Photo (autograph collectors) |
| ISP | Interactive String Processor |
| ISP | Infirmiers de Secteur Psychiatrique |
| ISP | Infrared Spectrophotometer |
| ISP | Index of Social Position |
| ISP | Islip, NY, USA - Long Island-Macarthur Airport (Airport Code) |
| ISP | Inter-American Strategy for Participation |
| ISP | International Signaling Point |
| ISP | Inner Strength Points (Palladium Games) |
| ISP | Initial State Probability |
| ISP | Input Signal Processing |
| ISP | International Service Personnel |
| ISP | Isolator Surge Protector |
| ISP | Internet Selective Polling |
| ISP | Installation Security Plan |
| ISP | Interactive Session Protocol |
| ISP | ISDN Security Program |
| ISP | Initial Spare Parts |
| ISP | Industrial Solid Propulsion Inc |
| ISP | Inverse Source Problem |
| ISP | Involuntary Separation Plan (HR term for layoff) |
| ISP | Installation Strategic Plan (US Army) |
| ISP | Infinity Science Press (Hingham, MA) |
| ISP | Identification Safety Point |
| ISP | Integrated Services Panel |
| ISP | Indexed Sequential Processor |
| ISP | Irish Society of Periodontology |
| ISP | Interlock Status Panel |
| ISP | Interim Support Program |
| ISP | Interim Support Period |
| ISP | Interleaving Scenario Pattern |
| ISP | Insensitive Munitions Policy |
| ISP | Intelligence Situation Report |
| ISP | ISDN Signal Processor |
| ISP | Interoperability Support Program |
| ISP | Integrated Systems Processor (OH-58D Helicopter) |
| ISP | International Society of Postmasters |