Barbara Wharton Low (March 23, 1920 – January 10, 2019) was a biochemist, biophysicist, and a researcher involved in discovering the structure of penicillin and the characteristics of other antibiotics. Her early work at Oxford University with Dorothy Hodgkin used X-ray crystallography to confirm the molecular structure of penicillin, which at the time was the largest molecule whose structure has been determined using that method. Later graduate work saw her study with Linus Pauling and Edwin Cohn before becoming a professor in her own right. Low's laboratory would accomplish the discovery of the pi helix, investigate the structure of insulin, and conduct research into neurotoxins.