Matthew Stanley Quay (September 30, 1833May 28, 1904) was an immensely powerful Pennsylvania political boss once dubbed a "kingmaker" by President Benjamin Harrison. "Boss" Quay's political principles and actions stood in contrast to an unusually attractive personality. He was a resident of Beaver, northwest of Pittsburgh, where his house has been designated as a National Historic Landmark. The Roberts-Quay House at Philadelphia was added to the National Register of Historic Places in 1976.