Gilbert Westacott Reynolds (10 October 1895 Bendigo - 7 April 1967 Mbabane), was a South African optometrist and authority on the genus Aloe.

Gilbert Reynolds arrived in Johannesburg with his parents in 1902, where his father started business as an optician. He received his education at St John's College where he was Victor Ludorum. After the outbreak of World War I he enlisted and saw active service in South West Africa and Nyasaland with the rank of captain. Having qualified as optometrist he joined his father's practice in 1921. Reynolds developed a keen interest in the bulbs and succulents of South Africa at about this time. When he started his own country practice about 1930, he was able to travel extensively and gradually narrowed his interests to Aloe.

Reynolds was guided in the early stages of his research by Dr I. C. Verdoorn and Dr R. A. Dyer of the Botanical Research Institute in Pretoria, later becoming the authority on Aloe and having an extensive knowledge of the genus in the field and under cultivation. To gather material for his book, he explored the entire country, collecting specimens, gathering data and taking photographs of the plants in their natural habitats. General Smuts, himself an avid collector and experienced botanist, wrote the foreword to the book. Before the publication of Reynolds' work, no comprehensive guide to the aloes had been compiled, except for various writings and monographs which did not attempt a complete coverage. He spent four weeks at Kew towards the end of 1960, checking the taxonomy, type specimens and identifications.