Mary Louise Fossler (September 14, 1868 – January 22, 1952) was an American chemist and chemistry professor.
Fossler is best known for her contributions to chemistry research and for her career as a professor at the University of Nebraska.
Fossler graduated from the University of Nebraska with a Bachelor of Science in chemistry in 1894, and then returned to complete a Master of Arts in chemistry.
Fossler was a pioneer for women pursuing careers in science in the early 20th century.
Margaret Rossiter's book Women Scientists in America: Struggles and Strategies to 1940 provides a frame of reference for that time period, stressing the significance of women's work and contributions in science and during that time.