List of Famous people who died at 91

Sir Oswald Nigel Amherst Cecil, KBE, CB was a British naval officer.

Manfred Bleuler was a Swiss physician and psychiatrist. Following in the footsteps of his father, doctoral supervisor, and colleague, Eugen Bleuler, Manfred Bleuler was devoted primarily to the study and treatment of schizophrenia. For his contributions, he received the Stanley R. Dean Award in 1970 and the Marcel Benoist Prize in 1972.

Patsy Ruth Miller was an American film actress who played Esméralda in The Hunchback of Notre Dame (1923) opposite Lon Chaney.

Erwin Madelung was a German physicist. He was born in 1881 in Bonn. His father was the surgeon Otto Wilhelm Madelung. He earned a doctorate in 1905 from the University of Göttingen, specializing in crystal structure, and eventually became a professor. It was during this time he developed the Madelung constant, which characterizes the net electrostatic effects of all ions in a crystal lattice, and is used to determine the energy of one ion.