Robert Graydon may refer to:
Robert Graydon (1671–1725), Irish politician, member of Parliament for Harristown, 1692–1693, and 1695–1699 Robert Graydon (1744–1800), Irish politician, member of Parliament for Harristown, 1768–1776, and for Kildare Borough, 1790–1797 Robert Murray Graydon (1890–1937), British novelist