Gladys Lillian Boyd (December 26, 1893[1] – October 24, 1970) was a Canadian paediatrician at the Hospital for Sick Children in Toronto.

[2][3] Boyd graduated as a physician in 1918 from the University of Toronto Faculty of Medicine, where she had been the Undergraduate Medical Women's Council's director.

She began a fellowship at the Hospital for Sick Children in Toronto in 1920 and was appointed the director of Endocrine Services in 1921.

[2] Boyd contacted Banting to get a vial of his new insulin extract in October 1922 to treat her 11-year-old patient, Elsie Needham, who was in a diabetic coma; she made a rapid and remarkable recovery.

[4] Boyd presented her research at the inaugural scientific meeting of the Society for the Study of Diseases of Children (now the Canadian Paediatric Society), reporting 20 cases of children with diabetes treated with insulin and concluding that "insulin will probably not cure but arrests the course of the disease".