Machiavellianism may refer to:

• Machiavellianism (politics), the political philosophy of Niccolò Machiavelli, often associated with various versions of political realism.
• Machiavellianism (psychology), a scale in personality psychology that measures one's cold affect and manipulative orientation.
  • Machiavellianism in the workplace

Machiavellian may refer to:

• The Machiavellian Moment, book by John G. A. Pocock- an analysis of Machiavelli's influence after his death.
• Machiavellian intelligence hypothesis, concept in primatology that deals with a primate's ability to be in a successful social engagement with other groups
• Machiavellian (horse), 1987–2004, an American racehorse