Greer Mill, also known as Greer Roller Mill, is a historic grist mill located near Alton, Oregon County, Missouri. Built in 1860 by Samuel W. Greer, a Confederate Army captain. The mill fell victim to bushwhackers who set if on fire but was rebuilt after the Civil War. It is a 2 1/2 story rectangular, frame mill building on a sandstone foundation. It has a side gable roof topped by a cupola. The mill operated until 1920.