| IAA | Igarka Airport | Igarka | RU |
| IAB | McConnell Air Force Base | Wichita | US |
| IAD | Dulles International Airport | Washington | US |
| IAG | Niagara Falls International Airport | Niagara Falls | US |
| IAH | George Bush Intercontinental Airport | Houston | US |
| IAM | In Amenas Airport | In Amenas | DZ |
| IAN | Bob Barker Memorial Airport | Kiana | US |
| IAO | Sayak Airport | Del Carmen (Siargao) | PH |
| IAQ | Bahregan Airport | Bahregan | IR |
| IAR | Tunoshna Airport | Yaroslavl | RU |
| IAS | Iasi Airport | Iasi | RO |
| IAU | Iaura Airport | Iaura | PG |
| IBA | Ibadan Airport | Ibadan | NG |
| IBB | General Villamil Airport | Isabela Island | EC |
| IBE | Ibague Airport | Ibague | CO |
| IBI | Iboki Airport | Iboki | PG |
| IBL | Indigo Bay Lodge | Indigo Bay Lodge | MZ |
| IBO | Ibo Airport | Ibo | MZ |
| IBP | Iberia Airport | Iberia | PE |
| IBR | Ibaraki Airport | Ibaraki | JP |
| IBT | Central Railway Station | Bologna | IT |
| IBZ | Ibiza Airport | Ibiza | ES |
| ICA | Icabaru Airport | Icabaru | VE |
| ICI | Cicia Island Airport | Cicia Island | FJ |
| ICK | Nieuw Nickerie Airport | Nieuw Nickerie | SR |
| ICL | Clarinda Municipal Airport | Clarinda | US |
| ICN | Incheon International Airport | Seoul | KR |
| ICO | Sicogon Island Airport | Sicogon Island | PH |
| ICR | Nicaro Airport | Nicaro | CU |
| ICS | Cascade Airport | Cascade | US |
| ICT | Mid-Continent Airport | Wichita | US |
| ICY | Icy Bay Airport | Icy Bay | US |
| IDA | Fanning Field | Idaho Falls | US |
| IDB | Idre Airport | Idre | SE |
| IDC | Chilonzuine Island Airport | Chilonzuine Island | MZ |
| IDF | Idiofa Airport | Idiofa | CD |
| IDG | Ida Grove Municipal Airport | Ida Grove | US |
| IDH | Idaho County Airport | Grangeville | US |
| IDI | Indiana Airport | Indiana | US |
| IDK | Indulkana Airport | Indulkana | AU |
| IDN | Indagen Airport | Indagen | PG |
| IDO | Santa Isabel do Morro Airport | Santa Isabel do Morro | BR |
| IDP | Independence Airport | Independence | US |
| IDR | Devi Ahilya Bai Holkar Airport | Indore | IN |
| IDY | Ile 'd' Yeu Airport | Ile 'd' Yeu | FR |
| IEG | Babimost Airport | Zielona Gora | PL |
| IEJ | Iejima Airport | Iejima | JP |
| IES | Goehlis Airport | Riesa | DE |
| IEV | Zhuliany International Airport | Kiev | UA |
| IFA | Iowa Falls Airport | Iowa Falls | US |
| IFF | Iffley Airport | Iffley | AU |
| IFH | Hesa Airport | Hesa | IR |
| IFJ | Isafjordur Airport | Isafjordur | IS |
| IFL | Innisfail Airport | Innisfail | AU |
| IFN | Shahid Beheshti International | Esfahan | IR |
| IFO | Ivano-FrankIvsk Int'l Airport | Ivano-FrankIvsk | UA |
| IFP | Laughlin Bullhead International Airport | Bullhead City | US |
| IGA | Inagua Airport | Inagua | BS |
| IGB | Ingeniero Jacobacci Airport | Ingeniero Jacobacci | AR |
| IGD | Igdir Airport | Igdir | TR |
| IGE | Tchongorove Airport | Iguela | GA |
| IGG | Igiugig Airport | Igiugig | US |
| IGH | Ingham Airport | Ingham | AU |
| IGL | Cigli Air Base | Izmir | TR |
| IGM | Kingman Airport | Kingman | US |
| IGN | Maria Cristina Airport | Iligan | PH |
| IGO | Chigorodo Airport | Chigorodo | CO |
| IGR | Cataratas Airport | Iguazu | AR |
| IGS | Manching Airport | Ingolstadt | DE |
| IGT | Sleptsovkskaya Airport | Nazran | RU |
| IGU | Cataratas International Airport | Foz do Iguacu | BR |
| IHA | Off-Line Point | Niihama | JP |
| IHC | Inhaca Airport | Inhaca | MZ |
| IHN | Qishn Airport | Qishn | YE |
| IHO | Ihosy Airport | Ihosy | MG |
| IHR | Iranshahr Airport | Iranshahr | IR |
| IHU | Ihu Airport | Ihu | PG |
| IIA | Inishmaan Airport | Inishmaan | IE |
| IIL | Ilam Airport | Ilam | IR |
| IIS | Nissan Island Airport | Nissan Island | PG |
| IJK | Izhevsk Airport | Izhevsk | RU |
| IJU | J. Batista Bos Filho Airport | Ijui | BR |
| IJX | Jacksonville Municipal Airport | Jacksonville | US |
| IKA | Imam Khomeini International Airport | Tehran | IR |
| IKB | Wilkes County Airport | Wilkesboro | US |
| IKE | Heliport | Ikerasak | GL |
| IKI | Iki Airport | Iki | JP |
| IKK | Greater Kankakee Airport | Kankakee | US |
| IKL | Ikela Airport | Ikela | CD |
| IKO | Nikolski Air Force Station | Nikolski | US |
| IKP | Inkerman Airport | Inkerman | AU |
| IKS | Tiksi Airport | Tiksi | RU |
| IKT | Irkutsk Airport | Irkutsk | RU |
| ILA | Illaga Airport | Illaga | ID |
| ILB | Ilha Solteira Airport | Ilha Solteira | BR |
| ILD | Alguaire Airport | Lleida | ES |
| ILE | Killeen Municipal Airport | Killeen | US |
| ILF | Ilford Airport | Ilford | CA |
| ILG | Greater Wilmington Airport | Wilmington | US |
| ILH | Illis Air Base | Illesheim | DE |
| ILI | Iliamna Airport | Iliamna | US |
| ILK | Ilaka Atsinanana Airport | Ilaka Atsinanana | MG |
| ILL | Willmar Airport | Willmar | US |
| ILM | New Hanover County Airport | Wilmington | US |
| ILN | Clinton Field | Wilmington | US |
| ILO | Iloilo International Airport | Iloilo | PH |
| ILP | Moue Airport | Ile des Pins | NC |
| ILQ | Ilo Airport | Ilo | PE |
| ILR | Ilorin International Airport | Ilorin | NG |
| ILU | Kilaguni Airport | Kilaguni | KE |
| ILX | Ileg Airport | Ileg | PG |
| ILY | Islay Airport | Islay | GB |
| ILZ | Zilina Airport | Zilina | SK |
| IMA | Iamalele Airport | Iamalele | PG |
| IMB | Imbaimadai Airport | Imbaimadai | GY |
| IMD | Imonda Airport | Imonda | PG |
| IMF | Imphal Airport | Imphal | IN |
| IMG | Inhaminga Airport | Inhaminga | MZ |
| IMI | Ine Island Airport | Ine Island | MH |
| IMK | Simikot Airport | Simikot | NP |
| IML | Imperial Airport | Imperial | US |
| IMM | Immokalee Airport | Immokalee | US |
| IMN | Imane Airport | Imane | PG |
| IMO | Zemio Airport | Zemio | CF |
| IMP | Imperatriz Airport | Imperatriz | BR |
| IMR | Rogoredo Railway Station | Milan | IT |
| IMT | Ford Airport | Iron Mountain | US |
| INA | Inta Airport | Inta | RU |
| INB | Independence Airport | Independence | BZ |
| INC | Hedong Airport | Yinchuan | CN |
| IND | Indianapolis International Airport | Indianapolis | US |
| INE | Chinde Airport | Chinde | MZ |
| INF | In Guezzam Airport | In Guezzam | DZ |
| ING | Lago Argentino Airport | Lago Argentino | AR |
| INH | Inhambane Airport | Inhambane | MZ |
| INI | Konstantin Veliki Airport | Nis | RS |
| INJ | Injune Airport | Injune | AU |
| INK | Wink Airport | Wink | US |
| INL | Falls International Airport | International Falls | US |
| INM | Innamincka Airport | Innamincka | AU |
| INN | Innsbruck Airport | Innsbruck | AT |
| INO | Inongo Airport | Inongo | CD |
| INP | Central Railway Station | Naples | IT |
| INQ | Inisheer Airport | Inisheer | IE |
| INR | Kincheloe Air Force Base | Sault Ste. Marie | US |
| INS | Af Aux Airport | Indian Springs | US |
| INT | Smith-Reynolds Airport | Winston-Salem | US |
| INU | Nauru Island International Airport | Nauru Island | NR |
| INV | Inverness Airport | Inverness | GB |
| INW | Winslow Airport | Winslow | US |
| INX | Inanwatan Airport | Inanwatan | ID |
| INY | Inyati Airport | Inyati | ZA |
| INZ | In Salah Airport | In Salah | DZ |
| IOA | King Pyrros Airport | Ioannina | GR |
| IOK | Iokea Airport | Iokea | PG |
| IOM | Ronaldsway Airport | Isle Of Man | IM |
| ION | Impfondo Airport | Impfondo | CG |
| IOP | Ioma Airport | Ioma | PG |
| IOQ | Heliport | Isortoq | GL |
| IOR | Kilronan Airport | Inishmore | IE |
| IOS | Eduardo Gomes Airport | Ilheus | BR |
| IOT | Heliport | Illorsuit | GL |
| IOW | Iowa City Airport | Iowa City | US |
| IPA | Ipota Airport | Ipota | VU |
| IPC | Mataveri International Airport | Easter Island | CL |
| IPE | Ipil Airport | Ipil | PH |
| IPG | Ipiranga Airport | Ipiranga | BR |
| IPH | Sultan Azlan Shah Airport | Ipoh | MY |
| IPI | San Luis Airport | Ipiales | CO |
| IPL | Imperial County Airport | El Centro | US |
| IPN | Usiminas Airport | Ipatinga | BR |
| IPR | Porta Garibaldi Station | Milan | IT |
| IPT | Lycoming County Airport | Williamsport | US |
| IPU | Ipiau Airport | Ipiau | BR |
| IPW | Railway Station | Ipswich | GB |
| IQA | Air Base | Al Asad | IQ |
| IQM | Qiemo Airport | Qiemo | CN |
| IQN | Qingyang Airport | Qingyang | CN |
| IQQ | Cavancha Airport | Iquique | CL |
| IQT | C.F. Secada Airport | Iquitos | PE |
| IRA | Kirakira Airport | Kirakira | SB |
| IRB | Iraan Municipal Airport | Iraan | US |
| IRC | Circle City Airport | Circle | US |
| IRD | Ishurdi Airport | Ishurdi | BD |
| IRE | Irece Airport | Irece | BR |
| IRG | Lockhart River Airport | Lockhart River | AU |
| IRI | Iringa Airport | Iringa | TZ |
| IRJ | La Rioja Airport | La Rioja | AR |
| IRK | Kirksville Municipal Airport | Kirksville | US |
| IRM | Igrim Airport | Igrim | RU |
| IRN | Iriona Airport | Iriona | HN |
| IRO | Birao Airport | Birao | CF |
| IRP | Matari | Isiro | CD |
| IRR | Ostiense Railway | Rome | IT |
| IRS | Kirsch Municipal | Sturgis | US |
| IRT | Tiburtina Railway Station | Rome | IT |
| IRU | Iranamadu SPB | Iranamadu | LK |
| IRZ | Santa Isable Rio Negro Airport | Santa Isabel Rio Negro | BR |
| ISA | Mount Isa Airport | Mount Isa | AU |
| ISB | Benazir Bhutto Intl Airport | Islamabad | PK |
| ISC | St. Mary's Airport | Isles Of Scilly | GB |
| ISD | Iscuande Airport | Iscuande | CO |
| ISE | Suleyman Demirel Airport | Isparta | TR |
| ISG | New Ishigaki Airport | Ishigaki | JP |
| ISH | Ischia Harbour | Ischia | IT |
| ISI | Isisford Airport | Isisford | AU |
| ISJ | Isla Mujeres Airport | Isla Mujeres | MX |
| ISK | Ozar Airport | Nasik | IN |
| ISL | Isabel Pass Airport | Isabel Pass | US |
| ISM | Kissimmee Municipal Airport | Kissimmee | US |
| ISN | Sloulin Field International Airport | Williston | US |
| ISO | Stallings Field | Kinston | US |
| ISP | Long Island MacArthur Airport | Islip | US |
| ISQ | Schoolcraft County Airport | Manistique | US |
| ISR | Railway Station | Salerno | IT |
| ISS | Wiscasset Airport | Wiscasset | US |
| IST | Ataturk Airport | Istanbul | TR |
| ISU | Sulaymaniyah International Airport | Sulaymaniyah | IQ |
| ISW | Alexander Field | Wisconsin Rapids | US |
| ITA | Itacoatiara Airport | Itacoatiara | BR |
| ITB | Itaituba Airport | Itaituba | BR |
| ITE | Itubera Airport | Itubera | BR |
| ITH | Tompkins County Airport | Ithaca | US |
| ITI | Itambacuri Airport | Itambacuri | BR |
| ITJ | Off-Line Point | Itajai | BR |
| ITK | Itokama Airport | Itokama | PG |
| ITM | Osaka Int'l (Itami) Airport | Osaka | JP |
| ITN | Itabuna Airport | Itabuna | BR |
| ITO | Hilo International Airport | Hilo | US |
| ITP | Itaperuna Airport | Itaperuna | BR |
| ITQ | Itaqui Airport | Itaqui | BR |
| ITR | Itumbiara Airport | Itumbiara | BR |
| ITT | Porta Susa Railway Station | Turin | IT |
| IUE | Hanan International Airport | Niue Island | NU |
| IUI | Heliport | Innarsuit | GL |
| IUL | Ilu Airport | Ilu | ID |
| IUM | Summit Lake Airport | Summit Lake | CA |
| IUS | Inus Airport | Inus | PG |
| IVA | Ampampamena Airport | Ambanja | MG |
| IVC | Invercargill Airport | Invercargill | NZ |
| IVG | Ivangrad Airport | Ivangrad | ME |
| IVH | Ivishak Airport | Ivishak | US |
| IVI | Isla Viveros Airport | Isla Viveros | PA |
| IVL | Ivalo Airport | Ivalo | FI |
| IVO | Chivolo Airport | Chivolo | CO |
| IVR | Inverell Airport | Inverell | AU |
| IVW | Inverway Airport | Inverway | AU |
| IWA | Yuzhny Airport | Ivanovo | RU |
| IWD | Gogebic County Airport | Ironwood | US |
| IWJ | Iwami Airport | Masuda | JP |
| IWK | Iwakuni Airport | Iwakuni | JP |
| IWO | Iwo Jima Air Base | Iwoto (Iwo Jima) | JP |
| IWS | West Houston Airport | Houston | US |
| IXA | Agartala Airport | Agartala | IN |
| IXB | Bagdogra Airport | Bagdogra | IN |
| IXC | Chandigarh Airport | Chandigarh | IN |
| IXD | Allahabad Airport | Allahabad | IN |
| IXE | Mangalore Airport | Mangalore | IN |
| IXG | Sambre Airport | Belgaum | IN |
| IXH | Kailashahar Airport | Kailashahar | IN |
| IXI | Lilabari Airport | Lilabari | IN |
| IXJ | Satwari Airport | Jammu | IN |
| IXK | Keshod Airport | Keshod | IN |
| IXL | Kushok Bakula Rimpoche Airport | Leh | IN |
| IXM | Madurai Airport | Madurai | IN |
| IXN | Khowai Airport | Khowai | IN |
| IXP | Pathankot Airport | Pathankot | IN |
| IXQ | Kamalpur Airport | Kamalpur | IN |
| IXR | Birsa Munda Airport | Ranchi | IN |
| IXS | Kumbhirgram Airport | Silchar | IN |
| IXT | Pasighat Airport | Pasighat | IN |
| IXU | Aurangabad Airport | Aurangabad | IN |
| IXV | Along Airport | Along | IN |
| IXW | Sonari Airport | Jamshedpur | IN |
| IXY | Kandla Airport | Kandla | IN |
| IXZ | Veer Savarkar Int'l Airport | Port Blair | IN |
| IYK | Kern County Airport | Inyokern | US |
| IZA | Reg. Da Zona da Mata Airport | Juiz De Fora | BR |
| IZM | Metropolitan Area | Izmir | TR |
| IZO | Izumo Airport | Izumo | JP |
| IZT | Ixtepec Airport | Ixtepec | MX |