McCauley Propeller Systems is an American aircraft propeller manufacturer, founded in Dayton, Ohio in 1938 by Ernest G. McCauley. At its peak, it was reportedly the world's largest aircraft propeller manufacturer, or at least the largest manufacturer of general aviation propellers. For most of its existence, McCauley was headquartered in or near Dayton. In the 21st century, its headquarters were moved to then-parent-company Textron Aviation's headquarters in Wichita, Kansas.