Stefan Marinov (Bulgarian: ?????? ???????) (1 February 1931 – 15 July 1997) was a Bulgarian physicist, researcher, writer and lecturer who promoted anti-relativistic theoretical viewpoints, and later in his life defended the ideas of perpetual motion and free energy.
In 1997 he self-published experimental results that confirmed classical electromagnetism and disproved that a machine constructed by Marinov himself could be a source of perpetual motion.
Devastated by the negative results, he committed suicide in Graz, Austria on 15 July 1997.