The West Fork Millicoma River is a tributary, about long, of the Millicoma River in the U.S. state of Oregon. Rising in northeastern Coos County near the Douglas County line, it flows generally southwest through the Elliott State Forest of the Southern Oregon Coast Range to the community of Allegany. There it joins the East Fork Millicoma River to form the Millicoma. In turn, the Millicoma, which is only about long, joins the South Fork Coos River to form the Coos River. The Coos River, itself only about long, empties into the eastern end of Coos Bay, which connects to the Pacific Ocean.