Ralph Erskine Cleland (20 October 1892 – 11 June 1971) was an American botanist.

He was also a professor at the Department of Botany at Indiana University.

Cleland's most seminal field of research concerned the genetics of the plant genus Oenothera.

[1][2] He discovered the structures of linked rings of meiotic chromosomes (not to be confused with ring chromosomes)[3] that, by their interference with functions such as chromosomal crossover explained the unusual genetics and reproduction of plants in the genus Oenothera.

[4][5] He was elected to the American Philosophical Society in 1932 and both the United States National Academy of Sciences and the American Academy of Arts and Sciences in 1942.