Harry Alvin Millis (May 14, 1873 — June 25, 1948) was an American civil servant, economist, and educator and who was prominent in the first four decades of the 20th century. He was a prominent educator, and his writings on labor relations were described at his death by several prominent economists as "landmarks". Millis is best known for serving on the "first" National Labor Relations Board, an executive-branch agency which had no statutory authority.