Smut may refer to:

• Smut (fungus), a group of plant parasitic fungi
• Smut (comics), an adult British comic title dating back to the 1980s
• Smut, a band based in Chicago, Illinois
• A colloquial term for obscenity in general or pornography in particular
• Jimmy Means, a former NASCAR driver nicknamed "Smut"
• "Smut", a song by Tom Lehrer from his 1965 album That Was the Year That Was, referencing the colloquial meaning of the term