| i.e. | id est (that is) |
| IAAI | International Airport Authority of India |
| IAC | Indian Airlines Corporation |
| IAEA | International Atomic Energy Agency |
| IARI | Indian Agricultural Research Institute |
| IAS | Indian Administrative Service |
| IATA | International Air Transport Association |
| IBM | International Business Machines |
| IBRD | International Bank for Reconstruction and Development (World Bank) |
| ICAR | Indian Council of Agricultural Research |
| ICBM | Inter Continental Ballistic Missile |
| ICC | International Cricket Council |
| ICFTU | International Confederation of Free Trade Unions |
| ICICI | Industrial Credit and Investment Corporation of India Limited |
| ICJ | International Court of Justice |
| ICMR | Indian Council of Medical Research |
| ICSE | Indian Certificate of Secondary Educa­tion |
| ICSI | Indian Company Secretaries Institute |
| ICU | Intensive Care Unit |
| ICWA | Indian Council of World Affairs |
| IDA | International Development Agency |
| IDBI | Industrial Development Bank of India |
| IDF | Infrastructure Debt Fund |
| IDO | International Defence Organization |
| IDPL | Indian Drugs and Pharmaceuticals Limited |
| IEEE | Institute of Electronics and Electrical Engineers |
| IELTS | International English Language Testing System |
| IFA | Indian Football Association |
| IFC | Industrial Finance Corporation, International Finance Corporation |
| IFCI | Industrial Finance Corporation of India |
| IFFCO | Indian Farmers Fertilizers Cooperative |
| IFFI | International Film Festival of India |
| IFPRI |  International Food Policy Research Institute |
| IFS | Indian Foreign Service; Indian Forest Service |
| IFTU | International Federation of Trade Unions |
| IGNOU | Indira Gandhi National Open Uni­versity |
| IIE |  International Institute of Education |
| IIPA | Indian Institute of Public Administration |
| IIS | Indian Institute of Sciences |
| IISCO | Indian Iron and Steel Company |
| IISS | International Institute of Strategic Stud­ies |
| IIT | Indian Institute of Technology |
| ILA | Indian Library Association |
| ILO | International Labour Organisation |
| IMA | Indian Military Academy |
| IMAP | Internet Mail Access Protocol |
| IMF | International Monetary Fund |
| INA | Indian National Army |
| INGCA | Indira Gandhi Gallery for Culture and Art |
| INS | Indian Naval Ship |
| INSAT | Indian National Satellite |
| INTELSAT | International Telecommunication Satellite |
| INTERPOL | International Police Organisation |
| INTUC | Indian National Trade Union Con­gress |
| IOC | Indian Oil Corporation |
| IP | Internet Protocol |
| IPC | Indian Penal Code |
| IPCL | Indian Petro-Chemicals Corporation Ltd |
| IPI | International Press Institute |
| IPKF | Indian Peace Keeping Force |
| IPO | Initial Public Offering |
| IPOs | Initial Public Offerings |
| IPS | Indian Police Service; Inter Press Service |
| IQ | Intelligence Quotient |
| IRBM | Intermediate Range Ballistic Missile |
| IRC | International Red Cross |
| IRCON |  Indian Railways Construction Company |
| IRDA | Insurance Regulatory and Development Authority |
| IRDP | Integrated Rural Development Programme |
| IRS | Indian Revenue Service |
| ISB | Indian Standard Bureau |
| ISBN | International Standard Book Number |
| ISDN | Integrated Services Digital Network |
| ISI | Indian Standards Institution; Inter Services Intelligence |
| ISKCON | International Society for Krishna Consciousness |
| ISM | Indian School of Mines |
| ISO | International Standards Organisation |
| ISP | Internet Services Provider |
| ISRO | Indian Space Research Organisation |
| IST | Indian Standard Time |
| ITBP | Indo-Tibetan Border Police |
| ITDC | Indian Tourism Development Corporation |
| ITES | Information Technology enabled services |
| ITI | Indian Telephone Industries<br> Industrial Training Institute |
| ITO | International Trade Organization |
| ITPO | Indian Trade Promotion Organisation |
| ITU | International Telecommunication Union |
| ITUC | Indian Trade Union Congress |
| IUPAP | International Union of Pure and Applied Physics |
| IVF | In-Vitro Fertilisation |
| IVM | In-vitro Maturation |
| JCO | Junior Commissioned Officer |
| JEE | Joint Entrance Examination |
| JMM | Jharkhand Mukti Morcha |
| JPEG | Joint Photographic Expert Group |