Marion Jones Clark was born on August 9, 1916 and graduated from Shelbyville High School in Shelbyville, Indiana, in 1934. She attended Stephens College in Columbia, Missouri, receiving her A.A. degree in 1936. Continuing with her undergraduate education, she attended Purdue University in Lafayette, Indiana, graduating with distinction with a B.S. in bacteriology and chemistry in 1938. She attended graduate school at the University of Wisconsin and earned an M.S. in medical microbiology in 1940. She was the recipient of a Wisconsin Alumni Research Foundation scholarship.

Marion Jones worked for the Department of Bacteriology at the State University of Iowa (now the University of Iowa) beginning in the July 1940. Working initially as the Assistant Hospital Bacteriologist and later as Assistant Professor of the Department of Bacteriology, her responsibilities included laboratory instructions for medical and dental students, nurses instruction, and a separate course for liberal arts and graduate students in diagnostic microbiology. Her research interests centered on tissue culture methods in microbiology and physiology. Clark is a member of many organizations, including the Society of American Bacteriologists, Sigma Xi and Iota Sigma Pi (national honors societies for women in chemistry).

Marion Jones Clark has had a long standing interest in orchestral music. She played viola in the orchestras at Stephens College, Purdue University and later in Iowa City. In 1959 she married Arnold Clark, a physicist who worked at the Lawrence Livermore National Laboratory, in Livermore, California. The Clarks retired in Livermore and volunteer in the local schools, assisting music students who play stringed instruments, and perform with the local community orchestra.