| Abbreviation | Definition |
|---|---|
| ICSS | Immanuel Christian Secondary School |
| ICST | Indiana Christian State Tournament |
| ICST | International Christian School of Tonga |
| ICSU | International Christian School Uijeongbu |
| ICSV | International Christian School of Vienna |
| ICSV | International Christian School Vienna |
| ICSW | Islamic Center of Southwest Washington |
| ICT | Islamic Center of Tucson |
| ICTA | International Christian Tennis Association |
| ICVM | International Christian Visual Media |
| IDA | International Dhamma Activities |
| IDAP | Intensive Domestic Abuse Program |
| IDCF | Imago Dei Christian Fellowship |
| IDCF | Inter Denominational Christian Fellowship |
| IDCF | Inter-Denominational Christian Fellowship |
| IDCI | Islamic Dawan Centre International |
| IDEA | Intelligent Design and Evolution Awareness |
| IDEA | International Discipleship and Evangelization Associates |
| IDEA | Internet Debaters and Evangelists Anonymous |
| IDF | Illinois Disciples Foundation |