Lionel Smith Beale (5 February 1828 – 28 March 1906) was a British physician, microscopist, and professor at King's College London.

[2] A year after graduating, Beale used his own funds to set up a laboratory for chemical and microscopic research and teaching.

[1] In 1853, when he was 25, King's College appointed him Professor of Physiology and General and Morbid Anatomy.

[1] In writing, teaching and public speaking, Beale was a leading proponent of the scientific method in medicine.

[3] He was a strong advocate of the value of microscopy, which he felt to be essential to understanding morbid growths and diseases.

[5] He was a passionate and vocal advocate of the view that there is an essential difference between living and inert matter.