Robert Grant Furlong (January 4, 1886 – March 19, 1973) was an American physician and politician who served one term as a Democratic member of the U.S. House of Representatives from Pennsylvania from 1943 to 1945.

He taught school at Roscoe, PA, in 1904 and 1905, and practiced medicine in Donora, Pennsylvania, from 1910 to 1968.

During the First World War, Furlong served as a first lieutenant with the Two Hundred and Eightieth Ambulance Company, Twentieth Division.

Furlong was elected as a Democrat to the Seventy-eighth Congress, but was an unsuccessful candidate for renomination in 1944.

He resumed the practice of medicine, and was elected sheriff of Washington County, Pennsylvania, serving from 1945 to 1961.