Olive Mary Hilliard
Olive Mary Hilliard (née Hillary) (4 July 1925 Durban) is a noted South African botanist and taxonomist.
Hilliard attended Natal University in the years 1943-47 where she obtained an MSc and later a PhD. She worked at the National Herbarium in Pretoria in 1947-48 and was a lecturer in botany at Natal University from 1954 to 1962. In 1963 she became curator of the herbarium at Natal University and a research fellow. Her special fields of interest were the flora of Natal and the taxonomy of Streptocarpus, Compositae and Scrophulariaceae.
In 1964 she formed a professional and personal collaboration with Brian Laurence Burtt (1913-2008) who played a large part in the revitalising of a moribund Royal Botanic Garden Edinburgh. Their collaboration resulted in numerous papers and three books, Streptocarpus: an African Plant Study (1971), The Botany of the Southern Natal Drakensberg (1987), and Dierama: The Hairbells of Africa (1991). 
Her collected specimens, mostly from the Natal Drakensberg and Malawi, number some 8 000 (of which 5 000 were collected with B. L. Burtt). She is commemorated in Plectranthus hilliardiae Codd, Schizoglossum hilliardiae Kupicha, Cymbopappus hilliardiae B.Nord., Agalmyla hilliardiae D.J.Middleton & S.M.Scott and Helichrysum hilliardiae Wild.
- Hilliard, OM, BL Burtt 1971. Streptocarpus: an African Plant Study
- Hilliard, OM. 1983. Flora of Southern Africa Series. Ed. Balogh Scientific Books. 325 pp. ISBN 0-621-07943-X
- Hilliard, OM, BL Burtt 1985. A Revision of Geranium in Africa south of the Limpopo. (Notes from the Royal Botanic Garden Edinburgh. Vol. XLII no. 2)
- Hilliard, OM. 1987. The Botany of the Southern Natal Drakensberg (Annals of Kirstenbosch Botanic Gardens) Ed. National Botanic Gardens. 253 pp. ISBN 0-620-10625-5
- Hilliard, OM, BL Burtt 1991. Dierama: The Hairbells of Africa. Ed. Timber Press, Inc. 152 pp. ISBN 1-874802-01-7
- Hilliard, OM. 1995. The Manuleae: A Tribe of Scrophulariaceae. Ed. Edinburgh University Press. 600 pp. ISBN 0-7486-0489-8
- Hilliard, OM, LS Davis (illustrator). 1997. Trees & Shrubs of Natal (Ukhahlamba). Ed. Univ. of Kwazulu Natal Press; 2ª ed. 48 pp. ISBN 0-86980-882-6
- Hilliard, OM. 1997. Flowers of the Natal Drakensberg: The Lily, Iris And Orchid Family And Their Allies (Ukhahlamba S.) Ed. Univ. of Kwazulu Natal Press. 85 pp. ISBN 0-86980-702-1