Lydia Maria Adams de Witt

Lydia Maria Adams DeWitt, born Lydia Maria Adams (February 1, 1859 - March 10, 1928) was an U.S. pathologist.

Lydia Maria Adams was born in Flint, Michigan, as second daughter of three children to Oscar and Elizabeth Adams (née Walton).

She became a teacher and married her colleague Alton D. DeWitt in 1878, with whom she would have two children (Stella, born 1879, and Clyde, born 1880).

In 1895, she began medical studies at the University of Michigan; she became M.D. in 1898 and B.S. in 1899. She continued to work at the University of Michigan under pathology professor George Dock until 1910, in the field of microscopic anatomy. When she, along with other female colleagues, was excluded from the university's research clubs in 1902, she started a local Women's Research Club.

In 1910, she and Dock moved to St. Louis, Missouri, where she worked as instructor of pathology at Washington University, as well as for the St. Louis Department of Health. Her interests switched to bacteriology and chemotherapeutics, including the chemotherapy of tuberculosis. She then moved to the University of Chicago in 1912, where she eventually became assistant professor.

DeWitt died in Winters, Texas.