The SpaceX Red Dragon was a 2011–2017 concept for using an uncrewed modified SpaceX Dragon 2 for low-cost Mars lander missions to be launched using Falcon Heavy rockets.

The primary objective of the initial Red Dragon mission was to test techniques and technology to enter the Martian atmosphere with equipment that a human crew could conceivably use. The series of Mars missions were to be technology pathfinders for the much larger SpaceX Mars colonization architecture that was announced in September 2016. An additional suggested use for a mission called for a sample return Mars rover to be delivered to the Martian surface.

The program was conceived in 2011 as a potential NASA Discovery mission launching as early as 2022, and evolved over several years once it did not receive NASA funding from the 2013–2015 Discovery Mission program cycle. In April 2016, SpaceX announced that they had signed an unfunded Space Act Agreement with NASA, providing technical support, for a launch no earlier than 2018. In February 2017, SpaceX noted this launch date was delayed to no earlier than 2020. In July 2017, Elon Musk announced that development would be halted and resources redirected to Starship.

SpaceX worked with NASA's Ames Research Center in 2011 to produce a feasibility study for a mission that would search for evidence of life on Mars (biosignatures), past or present. SpaceX's Dragon version 1 capsule is used to ferry cargo only, while SpaceX Dragon 2 transports astronauts to and from the International Space Station. The Red Dragon proposal called for modifications so it could be used to transport payload to Mars, land using retrorockets, and to become a precursor to a human mission to Mars.

SpaceX initially planned to propose Red Dragon for funding in 2013 and 2015 as the United States NASA Discovery mission #13 for launch in 2022, but it was not submitted.

The 2011 Red Dragon concept was conceived to use a modified 3.6-meter (12 ft) diameter Dragon module, with a mass of 6.5 tonnes (14,000 lb) and an interior volume of 7 cubic metres (250 cu ft) for up to 1 tonne (2,200 lb; 1,000 kg) of Mars-landed payload. The instruments were proposed to drill approximately 1.0 metre (3.3 ft) under ground to sample reservoirs of water ice known to exist in the shallow subsurface. The mission cost was projected in 2011 to be less than US$400 million, plus $150 million to $190 million for a launch vehicle and lander.

The goals for a NASA-funded mission, as originally proposed by NASA Ames Research Center, were:

A 2014 study of a potential 2021 NASA-funded Red Dragon mission suggested that it could offer a low-cost way for NASA to achieve a Mars sample return. In the concept, the Red Dragon capsule would be equipped with the system needed to return samples gathered on Mars, including a Mars Ascent Vehicle (MAV), an Earth Return Vehicle (ERV), and hardware to transfer the sample collected by a previously landed rover mission, such as NASA's planned Mars 2020 rover, to the ERV. The ERV would transfer the samples to high Earth orbit, where a separate future mission would pick up the samples and de-orbit to Earth. NASA did not fund either concept.