I
- Idutywa Taxi Association (ITA)
- iKapa Arms and Ammunition Collectors Association (IAACA)
- Ile De France Sheep Breeders’ Society (IDFSBS)
- Ilembe Chamber of Commerce, Industry and Tourism (ICCIT)
- Illumination Engineering Society of South Africa (IESSA)
- Inanda Crossroads Taxi Association (ICTA)
- Independent Communications Authority of South Africa (ICASA)
- Independent Dealer Association (IDA)
- Independent Development Trust (IDT)
- Independent Electoral Commission (IEC)
- Independent Municipal & Allied Trade Union (IMATU)
- Independent Producers Organisation (IPO)
- Independent Regulatory Board for Auditors (IRBA)
- Independent Schools Association of South Africa (ISASA)
- Independent South African National Civic Organisation (ISANCO)
- Indian Academy of South Africa (IASA)
- Indoor Cricket Association (ICA)
- Industrial Development Corporation of South Africa (IDC)
- Information Systems Audit and Control Association South Africa Chapter NPC (ISACA-SA)
- Information Technology Association of South Africa (ITA)
- Information Technology Users Council (ITUC)
- Inhlangano Yabelaphi Ngenkolo Nangokomoya (IYNN)
- Inkatha Freedom Party (IFP)
- Innovation for The Blind (IFB)
- Innovative Pharmaceutical Association South Africa (IPASA)
- Institute for African Alternatives (IFAA)
- Institute for Aviation Medicine (IAM)
- Institute for Commercial Forestry Research (ICFR)
- Institute for Futures Research (IFR)
- Institute for Global Dialogue (IGD)