SAAB — Svenska Aeroplan Aktiebolaget (Sweden)
- SAAB A-32A Lansen — Two-seat attack aircraft produced by SAAB from 1955 to 1960 for the Swedish Air Force (Flygvapnet)
Santos-Dumont — Santos-Dumont (France)
- Santos-Dumont Demoiselle — French single-engine single-seat pioneer monoplane
Saunders — Saunders Aircraft Company (Canada)
- Saunders ST-27-100 — Canadian Twin-engine Regional Airliner
Schneider Grunau — Schneider Grunau (Germany)
- Schneider Grunau Baby II B-2 — German single-Seat high-wing sailplane
Schweizer — The Schweizer Aircraft Corporation (USA)
- Schweizer LNS-1 — World War II Training Glider
- Schweizer TG-2 — World War II Training Glider
- Schweizer TG-3A — World War II Training Glider
Scottish Aviation — Scottish Aviation Limited (Scotland)
- Scottish Aviation Bulldog MDL 120-121 — British two-seat side-by-side training aircraft
- Scottish Aviation Twin Pioneer — British Twin-engine STOL transport aircraft
Seversky — Seversky Aircraft Company (USA)
- Seversky AT-12 Guardsman — Single-engine two-seat advanced monoplane trainer
- Seversky P-35A — Single-engine single-seat monoplane fighter
Shaanxi — Shaanxi Aircraft Company (China)
- Shaanxi Yun-8 (Y-8) Cub — Four-engine turbo-prop transport (Chinese An-12 Cub)
Sharp — John Sharp (USA)
- Sharp DR 90 Nemesis — Single-engine single-seat Formula-One racing monoplane
Shenyang — Shenyang Aircraft Corporation (China)
- Shenyang J-6 Farmer — Single-engine single-seat supersonic fighter (Chinese-built MiG-19 Farmer)
- Shenyang J-8II Finback — Single-engine single-Seat supersonic high-altitude interceptor fighter aircraft (NATO Finback)
Short — Short Brothers PLC (UK)
- Short Sunderland MR.5 — British World War II four-engined flying-boat patrol-bomber.
SIAI-Marchetti — Alenia Aermacchi (Italy)
- SIAI-Marchetti SF-260B — Single-engine light monoplane marketed as an aerobatics plane and a military trainer.
- SIAI-Marchetti SF-260C — Single-engine light monoplane marketed as an aerobatics plane and a military trainer.
- SIAI-Marchetti SF-260M — Single-engine light monoplane marketed as an aerobatics plane and a military trainer.
Siemens-Schuckert — Siemens-Schuckert (Germany)
- Siemens-Schuckert D.III — German World War I single-engine single-seat equal-span sesquiplane fighter
Sikorsky — The Sikorsky Aircraft Corporation (USA)
- Sikorsky SH-3A Sea King — USN anti-submarine warfare helicopter
- Sikorsky CH-3 Black Mariah — USAF long-range military transport helicopter
- Sikorsky YH-5A Dragonfly — Single-engine two-seat rescue helicopter
- Sikorsky H-5A Dragonfly — Single-engine two-seat rescue helicopter
- Sikorsky UH-19B Chickasaw — Single-engine rescue helicopter
- Sikorsky UH-19D Chickasaw — Single-engine rescue helicopter
- Sikorsky HH-34J Choctaw — Single-engine medium transport helicopter
- Sikorsky HH-52A Sea Guard — USCG single-engine search and rescue helicopter
- Sikorsky CH-53A Sea Stallion — U.S. Navy two-engine heavy-lift helicopter
- Sikorsky MH-53C Sea Dragon — Twin-engine heavy-lift helicopter
- Sikorsky CH-53E Super Stallion — Three-engine heavy-lift helicopter
- Sikorsky SH-60B Seahawk — Twin-engine anti-submarine warfare helicopter
- Sikorsky HH-60G Pavehawk — USAF Twin-engine search and rescue helicopter
- Sikorsky HO4S-3 Horse — Single-engine search and rescue helicopter
- Sikorsky R-4B Hoverfly I — Single-engine light military helicopter
- Sikorsky R-6A Hoverfly II — Single-engine light military helicopter
- Sikorsky S-38 Carnauba — American Twin-engine passenger amphibious aircraft
- Sikorsky S-58T — Single-turboshaft-engine, medium-lift commercial helicopter
SNIAS — Société Nationale Industrielle Aerospatiale (France)
- SNIAS AS350 Astar — French single-engine light helicopter.
Socata — Société de Construction d'Avions de Tourisme et d'Affaires (France)
- Socata Tampico TB-9C — Single-engine low-wing monoplane
Soko — Soko (Jugoslavia: Bosnia-Hercegovina)
- Soko G-2 Galeb — Two-seat single-engine jet trainer and ground-attack aircraft
Sonex — Sonex Aircraft LLC (USA)
- Sonex — Two-seat single-engine low-wing monoplane
Sopwith — Sopwith Aviation Company (UK)
- Sopwith 1½ Strutter — British WWI multi-role biplane
- Sopwith F.1 Camel — British WWI single-engine single-seat biplane fighter
- Sopwith 2F.1 Camel — British WWI single-engine single-seat biplane fighter
- Sopwith 5F.1 Dolphin Mk.I — British WWI single-engine single-seat biplane fighter
- Sopwith 7F.1 Snipe — British WWI single-engine single-seat biplane fighter
- Sopwith Pup — British WWI single-engine single-seat biplane fighter
- Sopwith Triplane — WWI single-engine single-seat triplane fighter
SPAD — Société Pour L'Aviation et ses Dérivés (France)
- SPAD S.VII — French WWI single-engine single-seat biplane fighter
- SPAD S.XIII — French WWI single-engine single-seat biplane fighter
- SPAD S.XVI — French WWI single-engine single-seat biplane fighter
SPAD-Deperdussin — Deperdussin (France)
- 1913 SPAD-Deperdussin Monocoque — French pioneer single-engine mid-wing monoplane racer
Spartan — Spartan Aircraft Company (USA)
- Spartan C-3-165 — Single-engine two-seat biplane
Spencer — Spencer Amphibian Air Car Inc. (USA)
- Spencer S-12-D Aircar — Single-engine four-seat amphibian high-wing monoplane
Sperry — Lawrence Sperry Aircraft Company (USA)
- Sperry M-1 Messenger — Single-engine single-seat parasite biplane
Stampe — Stampe et Renard (Belgium)
- Stampe SV-4B — Single-engine two-seat biplane sport/trainer
Standard — Standard Aircraft Corporation (USA)
- Standard E-1 (M-Defense) — American single-engine single-seat biplane fighter
- Standard J-1 Trainer — American single-engine two-seat biplane trainer
Starn — Starn-EAA (USA)
- Starn EAA Acro Sport — Single-engine single-seat sport biplane
Stearman — Stearman Aircraft Company (USA)
- Stearman 4E Senior Speedmail — Single-Engine Two-Seat Biplane Mail Delivery Aircraft
- Stearman 4EM Senior Speedmail — Single-Engine Two-Seat Biplane Mail Delivery Aircraft
Steen — Steen Aero Lab. Inc. (USA)
- Steen Skybolt 300 — Single-Engine Two-Seat Aerobatic Biplane
Stewart — Donald Stewart (USA)
- Stewart Headwind B — Single-engine single-seat light high-wing kit-built monoplane
Stinson — Stinson Aircraft Corporation (USA)
- Stinson 108-2 Voyager — Single-engine high-wing monoplane
- Stinson 108-3 Voyager — Single-engine high-wing monoplane
- Stinson Detroiter — Single-engine high-wing monoplane
- Stinson L-5 Sentinel — Single-engine high-wing monoplane
- Stinson L-5B Sentinel — Single-engine high-wing monoplane
- Stinson L-5E Sentinel — Single-engine high-wing monoplane
- Stinson L-5G Sentinel — Single-engine high-wing monoplane
- Stinson SM-8A Detroiter Junior — Single-engine high-wing monoplane
- Stinson SM-6000-B — Three-engine high-wing passenger monoplane
- Stinson SR Reliant — Single-engine high-wing monoplane
- Stinson SR-5E Reliant — Single-engine high-wing monoplane
- Stinson SR-9 Reliant — Single-engine high-wing monoplane
- Stinson SR-10G Reliant — Single-engine high-wing monoplane
- Stinson V77 — Single-engine high-wing monoplane
Stits — Ray Stits (USA)
- Stits DS-1 Baby Bird — Single-engine single-seat high-wing micro sport monoplane
- Stits SA-2A Sky Baby — Single-engine single-seat micro biplane
- Stits SA-3A Playboy — Single-engine single-seat micro biplane
Stoddard-Hamilton — Stoddard-Hamilton Aircraft Inc. (USA)
- Stoddard-Hamilton Glasair — Single-engine low-wing high performance monoplane
- Stoddard-Hamilton Glasair FT — Single-engine low-wing high performance monoplane
- Stoddard-Hamilton Glasair HAM 2 — Single-engine low-wing high performance monoplane
- Stoddard-Hamilton Glasair SH-2F — Single-engine low-wing high performance monoplane
- Stoddard-Hamilton Glasair SH-2R — Single-engine low-wing high performance monoplane
Stolp — Stolp Starduster Corp. (USA)
- Stolp SA-300 Starduster — Single-engine two-seat biplane
Supermarine — Supermarine Aviation Works. Ltd. (UK)
- Supermarine Seagull Mk.V — Single-pusher-engine biplane amphibian
- Supermarine Stranraer — British two-engine high-wing flying boat
Supermarine — Vickers-Armstrongs Ltd., Aircraft Section, Supermarine Division (UK)
- Supermarine Spitfire (replica) — British WWII single-engine single-seat low-wing monoplane fighter
- Supermarine Spitfire Mk.I — British WWII single-engine single-seat low-wing monoplane fighter
- Supermarine Spitfire Mk.Ia — British WWII single-engine single-seat low-wing monoplane fighter
- Supermarine Spitfire F.Mk.VIIc — British WWII single-engine single-seat low-wing monoplane fighter
- Supermarine Spitfire T.Mk.VIII — British WWII single-engine two-seat low-wing monoplane trainer/fighter
- Supermarine Spitfire Mk.IX — British WWII single-engine single-seat low-wing monoplane fighter
- Supermarine Spitfire L.F. Mk.IXe — British WWII single-engine single-seat low-wing monoplane fighter
- Supermarine Spitfire Mk.XI — British WWII single-engine single-seat low-wing monoplane fighter
- Supermarine Spitfire Mk.XIV — British WWII single-engine single-seat low-wing monoplane fighter
- Supermarine Spitfire Mk.XVI — British WWII single-engine single-seat low-wing monoplane fighter
- Supermarine Spitfire P.R. Mk.XIX — British WWII single-engine single-seat low-wing monoplane fighter
- Supermarine Spitfire F.24. — British WWII single-engine single-seat low-wing monoplane fighter
Swallow — Swallow Airplane Manufacturing Company (USA)
- Swallow TP — Single-engine two-seat biplane trainer
Swick-T — Swick Taylorcraft (USA)
- Swick-T — Single-engine high-wing aerobatic monoplane
Symphony — Ostmecklenburgische Flugzeugbau Symphony Aircraft Industries (Germany)
- Symphony OMF-100-160 — Single-engine two-seat high-wing monoplane