Clara Flora Lieber (July 10, 1902 – December 14, 1982) was an American chemist known for her work with Otto Hahn on discovering fission, and her discovery of several isotopes of strontium and barium.

Clara Lieber attended Smith College and earned an associate degree in 1923, the University of Chicago during the summer of 1924, and University College London, where she earned a bachelor's degree in 1936.

[1] After graduating from University College London, Lieber became a doctoral student at the Kaiser-Wilhelm Institute in 1936.

In 1939, she returned to the United States without a Ph.D. She married Otto Nothhacksberger after the war and served on the Committee for the Resettlement of Japanese-Americans.

[1][2] She died at Indiana University Medical Center on December 14, 1982, and was buried at Crown Hill Cemetery.