Lewis Ralph Jones (December 5, 1864 – April 1, 1945) was an American botanist and agricultural biologist.

He was a professor of plant pathology from 1904 to 1935 at the University of Wisconsin.

[2] Jones was elected to the United States National Academy of Sciences in 1920 and the American Philosophical Society in 1925.

[2] Jones' second wife was Anna May Clark, a fellow botanist.

This article about an American botanist is a stub.