Louise Guthrie (October 10, 1879 – February 20, 1966) was a South African botanist and botanical artist.

Isobel Louise Sophie Guthrie was born in Cape Town, Cape Colony in 1879, the daughter of English-born botanist and mathematics professor Francis Guthrie and his wife, Isabella Grisbrook.

[2] Louise Guthrie was a botanical assistant at the Bolus Herbarium, beginning in 1918, until 1927.

While there, she developed her skill as a botanical illustrator, best known for a series of 264 depictions of protea species found in South Africa, begun in 1925, with the last dated 1947.

The Hermanus Botanical Society held an exhibit of 76 paintings by Guthrie in 2000, at the Fernkloof Nature Reserve.