
An experimental aircraft is an aircraft that has not yet been fully proven in flight. Often, this implies that new aerospace technologies are being tested on the aircraft, though the label is more broad.

This is a list of experimental aircraft, or aircraft used or built to conduct experiments involving aerodynamics, structural materials, propulsion systems, configuration and equipment. Prototypes, pre-production and homebuilt aircraft described as experimental but which were not used in this manner outside their own development are excluded.

The Moskalyev SAM-13 was a prototype twin-engined single-seat low-wing fighter built in the Soviet Union in the 1930s.

The Caproni Ca.6 was a single-engine biplane designed and built by Caproni in the early 1910s.

The Caproni Ca.7 was a proposed biplane designed by Caproni in the early 1910s.
The Caproni Ca.8 was a single-seat monoplane designed and built by Caproni in the early 1910s.
The Caproni Ca.9 was a single-engine monoplane designed and built by Caproni in the early 1910s.
The Caproni Ca.11 was a single-engine monoplane designed and built by Caproni in the early 1910s.
The Caproni Ca.12 was a two-seater single-engine monoplane built by Caproni in the early 1910s.
The Caproni Ca.13 was a two-seater single-engine monoplane built by Caproni in the early 1910s.

The Caproni Ca.16 was a single-engine monoplane designed and built by Caproni in the early 1910s.

The Discovery Aviation Model 201 aka Avia Accord 201 is a light utility aircraft that was re-introduced in 2013.

The Fieseler F 4 was developed, built and flown as a two-seat sports and travel aircraft at the Fieseler Flugzeugbau.

The IAR-111 Excelsior is a supersonic mothership project, designed by ARCA Space Corporation, intended to transport a rocket payload up to 18,000 m (59,000 ft) and for developing space tourism related technologies. The aircraft is to be constructed almost entirely from composite materials, and will be designed for take-off and landing from the sea surface.

The Pegasus PE-210A is a prototype of a single-engine Trainer with canard developed by Oaxaca Aerospace and TechBA.

Preliminary Research Aerodynamic Design to Lower Drag, or Prandtl-D is an unmanned experimental glider-aircraft being developed by NASA. The acronym is a reference to early German Aerospace Engineer Ludwig Prandtl.

The Sack AS-6 was a German prototype circular-winged aircraft built privately during the Second World War.

The Scaled Composites 401 is an American experimental aircraft, designed and produced by Scaled Composites of Mojave Spaceport, Mojave, California, introduced in 2017. The two examples built were constructed for an unnamed customer to demonstrate "advanced, low-cost manufacturing techniques" for the production of research aircraft for both industry and government.

A testbed aircraft is an aeroplane, helicopter or other kind of aircraft intended for flight research or testing the aircraft concepts or on-board equipment. These could be specially designed or modified from serial production aircraft.

The Xplorair is a project of compact VTOL aircraft without rotating airfoil from aerospace engineer Michel Aguilar, funded by the French Armed Forces procurement agency DGA and supported by various European aeronautics firms such as Dassault Systèmes, EADS Innovation Works, MBDA, Altran Technologies, Sogeti, Turbomeca, COMAT Aerospace and the Institut Pprime. Announced in 2007, the project aimed to develop a UAV prototype scheduled for flight in 2017, followed by a single-seater flying car whose commercialization could occur the decade after.