1530s, "statement contrary to common belief or expectation," from Middle French paradoxe (14c.) and directly from Latin paradoxum "paradox, statement seemingly absurd yet really true," from Greek paradoxon, noun use of neuter of adjective paradoxos "contrary to expectation, incredible," from para- "contrary to" (see para-(1)) + doxa "opinion," from dokein "to appear, seem, think" (see decent). Meaning "statement that is seemingly self-contradictory yet not illogical or obviously untrue" is from 1560s.