Fallacy - something that is not true based on given evidence. Misconception - something that is not true based on a person's or group of people's faulty understanding of something Both of these words are similar, but I feel the word "misconception" describes information that is passed around as common knowledge and most people don't know that it is actually false. A fallacy, however, seems much stronger and tends to describe something that someone attempts to prove as true, but is unable to do so because their arguments are not sufficient.

The difference is the intention. A "fallacy" is an untruth, or lie, that is deliberate: "I knew his love was a fallacy when I saw him kissing Sara in the park" Misconception is an idea based on inaccurate information. "There was a great misconception that the world was flat."

the other answers are good but actually the meaning of the two words are almost the same