Self-contradiction or self-contradictory can refer to:

• Auto-antonym, a word with multiple meanings of which one is the reverse of another
• Formal fallacy, a pattern of reasoning rendered invalid by a flaw in its logical structure
• Oxymoron, a figure of speech that juxtaposes concepts with opposing meanings within a word or phrase that creates an ostensible self-contradiction
• Paradox, a logically self-contradictory statement or a statement that runs contrary to one's expectation
• Self-refuting idea, idea or statement whose falsehood is a logical consequence of the original

See also

• Contradiction
• Reductio ad absurdum