Arthur Martin Graffis ("Mike")(October 13, 1885 in Logansport, Indiana – November 4, 1933) was an American automotive engineer, serving as Chief Engineer of Auburn Automobile (1915–1922) and as Chief Engineer (1922–1932) and Interim President (1930) of Elcar Automotive.
He led a two-year battle (1931–33) to attract investors and save the company, but was killed in an automobile accident.
His grandfather, Abraham Graffis, built most of the covered bridges in Cass County, Indiana, and had substantial land holdings around Logansport.
His father, William Graffis, was an influential businessman, founder of Graffis & Sons Shoe Company, and an organizer of the Logansport State Bank.
His grandmother was a sister of prominent lawyer Henry Clay Thornton, father of Sir Henry Worth Thornton; Dr. William Patton Thornton, a prominent Cincinnati physician; and Dr. Joseph Lyle Thornton, a prominent educator and Past-President of the Ohio Valley Paper Company.