Dr. Gunsaulus died on March 17, 1921 at the age of 65 of heart failure. He suffered from several debilitating illnesses in his final years, but kept working at the Armour Institute while maintaining a demanding lecture schedule. His funeral was held at New England Congregational Church in Chicago on March 19. Officiating was Dr. Frederick F. Shannon, rector of Central Church. Dr. Shannon was assisted by Gunsaulus' brother-in-law, Dr. Clarence T. Brown of the Austin Congregational Church, and Reverend Charles W. Gilkey of the Hyde Park Baptist Church.