- Honolulu, Oahu (HNL)
- Hoquiam (HQM)
- Hot Springs (HOT)
- Houlton (HUL)
- Houston (CXO)
- Houston (EFD)
- Houston (HOU)
- Houston (IAH)
- Houston (SGR)
- Huntington (HTS)
- Huntsville (HSV)
- Huntsville (HTV)
- Huron (HON)
- Huslia (HSL)
- Hutchinson (HUT)
- Hyannis (HYA)
- Idaho Falls (IDA)
- Iliamna (ILI)
- Imperial (IPL)
- Indianapolis (IND)
- International Falls (INL)
- Islip (ISP)
- Ithaca (ITH)
- Jackson (JAC)
- Jackson (JAN)
- Jackson (JXN)
- Jackson (MKL)
- Jacksonville (CRG)
- Jacksonville (JAX)
- Jacksonville (LRF)
- Jacksonville (NIP)
- Jacksonville (NRB)
- Jacksonville (VQQ)
- Jamestown (JHW)
- Jamestown (JMS)
- Johnstown (JST)
- Jonesboro (JBR)
- Joplin (JLN)
- Junction (JCT)
- Juneau (JNU)
- Kahului (OGG)
- Kailua-Kona (KOA)
- Kalamazoo (AZO)
- Kalispell (FCA)
- Kaneohe (NGF)
- Kankakee (IKK)
- Kansas City (MCI)
- Kansas City (MKC)
- Kapolei (JRF)
- Kaunakakai (MKK)
- Kearney (EAR)
- Keene (EEN)
- Kekaha (BKH)
- Kelso (KLS)
- Kenai (ENA)
- Kenosha (ENW)
- Ketchikan (KTN)
- Key Largo (OCA)
- Key West (EYW)
- Key West (NQX)
- Kiana (IAN)
- Kincheloe (CIU)
- King Salmon (AKN)
- Kingman (IGM)
- Kingsford (IMT)
- Kingsville (NQI)
- Kinston (ISO)
- Kirksville (IRK)
- Klamath Falls (LMT)
- Klawock (KLW)
- Knob Noster (SZL)
- Knoxville/Maryville (TYS)
- Kodiak (ADQ)
- Kotzebue (OTZ)
- La Crosse (LSE)
- Lafayette (LFT)
- Lahaina (JHM)
- Lake Charles (LCH)
- Lake Havasu City (HII)
- Lakehurst (NEL)
- Lakeland (LAL)
- Lamar (LAA)
- Lanai City (LNY)
- Lancaster (LNS)
- Lancaster (WJF)
- Lander (LND)
- Lansing (LAN)
- Laramie (LAR)
- Laredo (LRD)
- Las Cruces (LRU)
- Las Vegas (LAS)
- Las Vegas (LSV)
- Las Vegas (LVS)
- Las Vegas (VGT)
- Latrobe (LBE)
- Lawrence (LWM)
- Lawton (LAW)
- Lebanon (LEB)
- Leesburg (LEE)
- Lemoore (NLC)
- Lewisburg (LWB)
- Lewiston (LWS)
- Lewistown (LWT)
- Lexington (LEX)
- Liberal (LBL)
- Lihue, Kauai (LIH)
- Lincoln (LNK)
- Little Rock (LIT)
- Livingston (LVM)
- Logan (LGU)
- Lompoc (VBG)
- London (LOZ)
- Long Beach (LGB)
- Longview (GGG)
- Los Angeles (LAX)
- Louisville (LOU)
- Louisville (SDF)
- Loveland (FNL)
- Lovelock (LOL)
- Lubbock (LBB)