R
- R & B, R & B Aircraft Company – United States
- RACA, Representaciones Aero Comerciales Argentinas SA – Argentina
- Radab, AB Radab – Sweden
- Radiant Power Corp., Radiant Power Corp. – A Heico Company – United States
- RAF (1), Royal Aircraft Factory – United Kingdom, > Royal Aircraft Establishment
- Rad Aviation, Kidlington, United Kingdom
- Ragwing, RagWing Aircraft Designs – United States
- Rainbow, Rainbow Aircraft (Pty), Ltd. – South Africa
- Rand, Kenneth Rand – United States
- Rand, Rand Robinson Engineering, Inc. – United States
- Ranger Aircraft Corp. – United States (1929, Oklahoma City OK, upon acquiring design and production rights of Coffman Monoplanes Inc.)
- Rans, Rans, Inc. – United States (Randy Schlitter, Hays KS) kit-built small aircraft
- Raven Rotorcraft, Boulder Colorado and later El Prado, New Mexico, United States
- Ravin, SA Ravin Composite Aircraft Manufacturers – South Africa
- Raytheon, Raytheon Aircraft Company – United States
- Raytheon, Raytheon Corporate Jets, Inc. – United Kingdom
- Rearwin, Rearwin Aircraft & Engines, Inc. – United States
- Rearwin, Rearwin Airplanes, Inc. – United States
- Reda, Reda-MDT, Ltd. – Russia
- Redback Aviation, Hoppers Crossing, Victoria, Australia
- Redfern, Walter Redfern Company – United States
- Reflex, Reflex Fiberglass Works, Inc. – United States
- Reflex Paramoteur, Chatou, France
- Regio Aviasi Industri, PT. Regio Aviasi Industri - Indonesia
- Régy Frères, Régy Frères – France
- Reims, Reims Aviation SA – France
- Renaissance (1), Renaissance Composites, Inc. – United States
- Renaissance (2), Renaissance Aircraft LLC – United States
- Renard, Robert Renard – France
- Renard, George & Alfred Renard
- Replica Plans, Replica Plans – Canada
- Republic, Republic Aviation Corporation – United States, (1939–?)
- Revolution, Revolution Helicopter Corporation, Inc. – United States
- Rhein, Rhein-Flugzeugbau GmbH – Germany, (RFB)
- Rhein-West-Flug, Rhein-West-Flug Fischer und Companie – Germany
- Rihn, Dan Rihn – United States
- Rihn, Rihn Aircraft Corporation – United States
- Rikugun, Rikugun Kokugijutsu Kenkyujo – Japan, (Army Aerotechnical Research Institute)
- Riley, Riley Aeronautics Corporation – United States, (?-1983) > Advanced Aircraft Corp
- Riley, Riley Aircraft Corporation – United States
- Riley, Riley Aircraft Manufacturing, Inc. – United States
- Riley, Riley International Corporation – United States
- Riley, Riley Turbostream Corporation – United States
- RLU, Charles B. Roloff, Robert Liposky and Carl Unger – United States
- Robin, Avions Pierre Robin – France, (1969–present)
- Robin, Avions Pierre Robin, Inc. – Canada
- Robin, Robin Aviation – France
- Robinson, Robinson Helicopter Company – United States
- Rock, J. Rock Segelflugzeugbau – Germany
- Rocket, Rocket Aircraft Company – United States
- Rockwell, Rockwell International Corporation – United States, (1966–1996) > Boeing North American
- Rockwell-MBB, see ROCKWELL and MBB – United States/Germany
- Rogerson Hiller, Rogerson Hiller Corporation – United States
- Rogozarski, P. S. F. A. -Rogozarski – Yugoslavia, (1924–1941) (First Serbian Aircraft Factory-Rogozarski)
- Rokospol Aviation, Prague, Czech Republic
- Rolladen-Schneider, Rolladen-Schneider Flugzeugbau GmbH – Germany
- Rollason, Rollason Aircraft and Engines, Ltd. – United Kingdom
- Roll Flight, Schwelm, Germany
- Romaero, SC Romaero SA – Romania
- Rose, Rose Aeroplane and Motor Company – United States
- Rotary Air Force, Rotary Air Force, Inc. – Canada
- Rotec, Rotec Engineering, Inc. – United States
- Rotor Flight Dynamics, Wimauma, Florida, United States
- Rotortec GmbH, Görisried, Allgäu, Germany
- RotorWay International, Chandler, Arizona, United States
- Rotorwing-Aero, Salt Lake City, Utah, United States
- Rouchaud, F. Rouchaud, Construction Aéronautique – France
- Rousseau, Etablissements Rousseau Aéronautique – France
- RTAF, Royal Thai Air Force – Thailand
- RUAG, RUAG Aerospace – Switzerland
- Rumpler, Edmund Rumpler – Austria, (Rumpler Flugzeugwerke GmbH)
- Rupert, Charles Rupert Joses – Brazil
- Ruschmeyer, Ruschmeyer Luftfahrttechnik GmbH – Germany
- Rusjan Brothers, Rusjan Brothers – Austro-Hungarian Empire, (Edvard & Josiph (Jože) Rusjan)
- Rutan, Rutan Aircraft Factory – United States, (Scaled Composites)
- RWD, Rogalski, Wigura and Drzewiecki – Poland
- Ryan, Ryan Aeronautical Company – United States