Richard Wettstein (30 June 1863 in Vienna – 10 August 1931 in Trins) was an Austrian botanist. His taxonomic system, the Wettstein system was one of the earliest based on phyletic principles.
Wettstein studied in Vienna, where he was a disciple of Anton Kerner von Marilaun (1831-1898) and married his daughter Adele. He was a professor at the University of Prague from 1892, and at the University of Vienna from 1899. He newly laid out the Botanical Garden of the University of Vienna.
In 1901 he became president of the Vienna Zoological-Botanical Society (Zoologisch-Botanische Gesellschaft), and during the same year took part in a scientific expedition to Brazil. In 1919 he was appointed vice-president of the Vienna Academy of Sciences. During his later years (1929–30), he traveled with his son, Friedrich, to eastern and southern Africa.
The mycological genus Wettsteinina is named in his honor. In 1905, he was co-president of the International Botanical Congress, held in Vienna.
- Nolanaceae, Solanaceae, Scrophulariaceae in (Engler & Prantl 1895, pp. 1–107).
- Grundzüge der geographisch-morphologischen Methode der Pflanzensystematik, 1898 - Basics of geographical-morphological methods of plant systematics.
- Botanik Und Zoologie In Österreich in den Jahren 1850 Bis 1900, 1901 - Botany and zoology in Austria in the years 1850 to 1900.
- Der Neo-Lamarckismus und seine Beziehungen zum Darwinismus, 1903 - Neo-Lamarckism and its relationship to Darwinism.