Robert Graydon may refer to two Irish politicians:
- Robert Graydon (1671–1725), member of Parliament for Harristown from 1692 to 1693 and from 1695 to 1699
- Robert Graydon (1744–1800), member of Parliament for Harristown from 1768 to 1776, then for Kildare Borough from 1790 to 1797