Gwendoline Joyce Lewis (1909–1967) was a South African botanist.
[1] She was active in the description and classification of species of the family of the Iridaceae.
She was botanist at the Bolus Herbarium of the University of Cape Town for 2 years and then was appointed curator of the South African Museum Herbarium.
In 1956 this herbarium and its staff moved to Kirstenbosch National Botanical Garden.
[1] Lewis was appointed a Research Officer with the National Botanical Gardens.