Luís Wittnich Carrisso (14 February 1886 – 14 June 1937) was a Portuguese botanist, professor at the University of Coimbra.

Carrisso was born in Figueira da Foz.^[1] He attended the Faculty of Philosophy of University of Coimbra (1904-1910). After graduating he became a student of botanist Julio Augusto Henriques.^[1] Carrisso took interest in evolution and heredity and presented his PhD thesis Hereditariedade in 1911. He published scientific work on ecology and plant systematics.^[1]

In 1918, he became Professor of Botany at University of Coimbra's Botanical Garden.^[1] He was a supporter of Charles Darwin's theory of evolution but was skeptical of the role of natural selection. He embraced mutationism.^[1]

He died on 6 June 1937 in the Namib desert (Moçâmedes), in Angola, of cardiac syncope, during his third botanical expedition to that country. A monument was erected at the site in his memory.^[2]

• Carrissoa