Boris Rajewsky (Russian: Борис Николаевич Раевский; Ukrainian: Борис Миколайович Раєвський; 17 July 1893 – 22 November 1974) was a Russian-born German biophysicist, who was one of the most influential researchers on the impact of radiation on living organisms in the 20th century.
He was the son of a Ukrainian noble family and grew up in the Russian Empire.
He studied physics at the St. Vladimir Imperial University of Kiev from 1912, and obtained a doctorate there in 1918.
He became the assistant of Friedrich Dessauer and obtained an additional doctorate at the Goethe University in 1929.
From 1946 he was chairman of the scientific council of the Max Planck Society, and in 1955, he became an adviser to the German Atomic Commission, a body of experts appointed by the federal government.