Samuel Gibson Dixon (March 23, 1851 - February 26, 1918) was an American lawyer, physician, sanitarian for the state of Pennsylvania and bacteriologist who made important contributions to the treatment and prevention of tuberculosis in the late 19th century and early 20th century.

Due to recurring illness, he chose to change profession and attended the medical department of the University of Pennsylvania, earning the Doctor of Medicine degree in 1886.

[3][1] He attended medical school at both King's College London and Pettenkofer's Laboratory of Hygiene in Munich.

[4] He is now regarded as the first researcher to induce immune response to tuberculosis in guinea pigs—a precursor to the development of an effective treatment for the infection in humans.

[5] He was appointed to the Board of Public Education in Philadelphia and eventually as the commissioner of health of the State of Pennsylvania.