- Silverhorn Ranch AirportIdent: US-6825Serves: Freer
- Silverton Municipal AirportIdent: 79XSServes: Silverton
- Silvies Valley Ranch AirportIdent: OG14Serves: Seneca
- Simko FieldIdent: 1ID9Serves: Inkom
- Simon FieldIdent: ND15Serves: Hannover
- Simons AirfieldIdent: 1WN5Serves: Land-O-Lakes
- Simons AirportIdent: 34COServes: Aurora
- Simonson FieldIdent: 80COServes: Pueblo
- Simpson AirportIdent: 9W3Serves: Philippi
- Simpson AirportIdent: ID62Serves: Grace
- Simpson AirportIdent: NE09Serves: Norfolk
- Simpson FieldIdent: MS61Serves: Picayune
- Simpsonville AirportIdent: VG12Serves: Rhoadesville
- Sindt AirportIdent: 15NEServes: Upland
- Sinele StripIdent: 06ISServes: Nauvoo
- Singleton AirportIdent: 97VAServes: Warm Springs
- Singleton's Landing StripIdent: IN87Serves: Knox
- Sioux County Regional AirportIdent: KSXKServes: Maurice
- Siskiyou County AirportIdent: KSIYServes: Montague
- Sisseton Municipal AirportIdent: K8D3Serves: Sisseton
- Sisters Eagle Air AirportIdent: K6K5Serves: Sisters
- Situk AirportIdent: A68Serves: Yakutat
- Six Oaks AirportIdent: NC67Serves: Fletcher
- Six Ponds AirportIdent: 3NY6Serves: Duanesburg
- Six Springs Ranch AirportIdent: OG51Serves: Madras
- Sixmile Lake AirportIdent: AA06Serves: Anchorage
- SJ AirfieldIdent: US-6887Serves: Sheffield
- Sjule Private AirstripIdent: 7NA9Serves: Souris
- Skaar Farm AirfieldIdent: ND84Serves: New Rockford
- Skagit Regional AirportIdent: KBVSServes: Burlington
- Skagway AirportIdent: PAGYServes: Skagway
- Skala AirportIdent: PN55Serves: Mc Clellandtown
- Skalitsky AirportIdent: 6TE0Serves: Edcouch
- Skamokawa East Valley AirportIdent: 18JYServes: Skamokawa
- Skarda / Tollville AirportIdent: 21ARServes: De Valls Bluff
- Skeen Ranch AirportIdent: 82NMServes: Hondo
- Skellytown AirportIdent: 3TE6Serves: Skellytown
- Skelton AirportIdent: AK04Serves: Eureka
- Ski Harbor AirportIdent: 67MOServes: Pittsburg
- Ski Valley AirparkIdent: US-0009Serves: McCall
- Skiatook Municipal AirportIdent: 2F6Serves: Skiatook
- Skid Marks AirportIdent: AK67Serves: Willow
- Skid Row AirparkIdent: 42XAServes: Golinda
- Skida Patch AirportIdent: 2XS4Serves: Bells
- Skidmo AirportIdent: 33WYServes: Etna
- Skinner Ranch AirportIdent: 12ORServes: Jordan Valley
- Skinners Wholesale Nursery AirportIdent: 16FDServes: Crescent City
- Skinningsrud AirportIdent: 6ND9Serves: Berthold
- Skip's Place AirportIdent: 2IN0Serves: Ossian
- Skis Landing Area AirportIdent: CT07Serves: Colchester
- Skovhus AirportIdent: VA24Serves: Concord
- Skwentna AirportIdent: PASWServes: Skwentna
- Sky Acres AirportIdent: 1XA1Serves: Bowie
- Sky Acres AirportIdent: K44NServes: Millbrook
- Sky Acres AirportIdent: VT25Serves: South Burlington
- Sky Blue AirfieldIdent: 6MN0Serves: Ponsford
- Sky Bryce AirportIdent: VG18Serves: Basye
- Sky Glen AirportIdent: MA75Serves: Uxbridge
- Sky Harbor AirportIdent: 9AK5Serves: Anchorage
- Sky Harbor AirportIdent: KDYTServes: Duluth