Adelchi Negri (16 July 1876 – 19 February 1912) was an Italian pathologist and microbiologist born in Perugia. He studied medicine and surgery at the University of Pavia, where he was a pupil of Camillo Golgi (1843–1926). After graduation in 1900, he became an assistant to Golgi at his pathological institute. In 1909 Negri became a professor of bacteriology, and the first official instructor of bacteriology in Pavia. On 19 February 1912 he died of tuberculosis at age 35.