Philipp Gross (September 30, 1899 – May 20, 1974) was a physical chemist born and educated in Vienna. He became Professor of Physical Chemistry at Vienna University but was expelled on racial grounds in 1938 under the Nazi regime. In 1939 he sought refuge in Britain, joining the physics department at Bristol University. On the outbreak of war, after a brief internment as an enemy alien, he returned to Bristol University and then worked in Industry. After the war he became Chief Scientist at the newly founded Fulmer Research Institute, a post which he occupied for more than twenty years. He was one of the first to apply rigorous to problems in extractive metallurgy and was the inventor of the sub-chloride process for the extraction of aluminium.