I
- I Heart Lung
- I Love Leon
- I Mother Earth (musician)
- I Power Solutions
- I Want Media
- I Was a King
- i-Independent TV
- I-League
- I.C.N.A. Center
- IAC/InterActiveCorp
- IAG Company
- IAG Research
- IAMGOLD Corporation
- Ian Dury (musician)
- Iarnrod Eireann
- Iasis Healthcare
- IAUDIO (Corporate)
- IAWS Group plc
- Ibbotson Associates
- Iberdrola
- IBM
- IBN18 Broadcast
- IBP (Company)
- IBP Company
- ICAAN
- ICAP
- Icarius de Menezes (designer)
- Iccon Oil and Specialities
- ICDS (Company)
- ICDS Limited
- Iceberg (designer)
- ICES Software
- ICF International, Inc.
- Ichalkaranji Soya
- ICI India
- ICICI Bank
- ICICI Bank (PP)
- ICICI Bank Limited
- ICICI Direct.com
- ICICI Lombard General Insurance Co. Ltd.
- ICICI Power
- ICICI PP
- ICICI Premier
- ICICI Prudential Life Insurance Co. Ltd
- ICICI Prudential Mutual Fund
- Icicon Electronics
- ICO, Inc.
- ICON Biopharma And Healthcare
- ICON plc
- Iconix Brand Group, Inc.
- ICOP Digital, Inc.
- ICP Securities
- ICRA
- ICSA India
- ICT Group, Inc.
- ICU Medical, Inc.
- ICU – In Paris
- Idaho State Bengals (basketball)
- Idaho State Bengals (football)
- Idaho Vandals (basketball)
- Idaho Vandals (football)
- IDB Group
- IDBI Bank
- IDBI Div I NIT 95
- IDBI Fortis Life Insurance Company Ltd
- IDBI Grow I NIT 95
- IDBI MF-Tax I NIT96
- IDBI Paisa Builder
- Idbyme
- IDC China Telecommunication
- Idea Cellular
- Ideal Carpets
- Ideal Federal Savings Bank
- Ideal Hotels and Industries
- Ideal Optics
- Ideal Space Solutions
- Idearc, Inc
- ideeli
- Idenix Pharmaceuticals, Inc.
- IDEXX Laboratories, Inc.
- IDFC
- IDFC Mutual Fund
- IDI (Company)
- IDI Ltd
- IDL-Salzbau (India)
- IDT Corporation
- IEC Education
- IEEE Spectrum
- IFB Agro Industries
- IFB Finance