Alexander Thomas Glenny (18 September 1882 – 5 October 1965), was a British immunologist known particularly for his work on the prevention of diphtheria.

Glenny was born in Camberwell, London, England, educated at Alleyn's School, Dulwich, and awarded a B.Sc.

[1] In 1899 Glenny started working for the Wellcome Physiological Research Laboratories, then in Central London, becoming head of the immunology department in 1906.

He worked on immunizations and antitoxins against diseases, including tetanus and diphtheria, and, later, chemical weapons.

Glenny's scientific work focused on the mechanisms of antibody production and the prevention of diphtheria.