Reinhold Ewald (born 18 December 1956) is a German physicist and ESA astronaut.

Born in Mönchengladbach, West Germany, he received a Diploma in experimental physics from the University of Cologne in 1983 and a Ph.D. in 1986, with a minor degree in human physiology.

In 1990, he was selected to the German astronaut team, training for the Mir '92 mission.

He performed experiments in biomedical and material sciences, and carried out operational tests in preparation for the International Space Station.

He served as an Advisor to the Head of Director General's Cabinet at ESA's headquarters in Paris from 2011 to 2014, followed by a position at the European Astronaut Centre in Cologne, promoting the scientific achievements of the ESA research programme on the International Space Station.