Lyster Hoxie Dewey (1865–1944) was an American botanist from Michigan.
He was born in Cambridge, Michigan. In 1888, he graduated from Michigan Agricultural College where, for the next two years, he taught botany.
Dewey was an assistant botanist of the United States Department of Agriculture from 1890 to 1902, and thereafter botanist in charge of fiber investigations and fiber plants research.
In 1911, he was the U.S. representative to the International Fibre Congress, held in Surabaya on Java island, in the Dutch East Indies (present day Indonesia).
His publications comprised bulletins of the United States Department of Agriculture, on:
He wrote about growing exotically named varieties of hemp on USDA research land in Virginia known as the Arlington Experimental Farm, site of the present day Pentagon.