Ruby Green Smith (January 6, 1878 – May 13, 1960) was an American entomologist, peace campaigner and home economics educator.

[3] She also worked as assistant director of the Conservation Division of the New York State Food Commission, and with the U.S. Department of Agriculture, before her retirement in 1946.

[8] In 1915, as Ruby G. Smith, Ph.D., she contributed a chapter, "Race Problems of World Contact" to the anti-war book The Overthrow of the War System, published in conjunction with the Woman's Peace Party, of which she was an active member.

[1] On 16 August 1905, she married a second time, at Stockton, California, to Albert William Smith (1856–1942), who had been head of mechanical engineering at Stanford University from 1891 to 1904, and was then dean of Cornell's Sibley College until his retirement in October 1921.

[10] Smith founded the Cayuga Bird Club in the fall of 1913,[15][16] and the Ithaca Housewives' League and Farmers' Market.