Purity means that a substance is all the same. There are no contaminants or other things added. The word also means no badness in a person's character.

Purity may also refer to:

• An indication of the amount of other gases in a particular gas
• Purity, a 1916 movie.
• A measure of correlation between a system and its environment,
• "Purity", a song by Slipknot on their debut self-titled album
• Purity in Buddhism, a spiritual purity of character or essence
• Purity Dairies, a dairy company in Nashville, Tennessee, United States
• Purity Factories, a food processing company in St. John's, Newfoundland, Canada
• Purity Distilling Company, an alcohol manufacturer involved in the Boston Molasses Disaster in the United States
• Black oil (also known as Purity), a fictional alien virus in the TV series The X-Files
• Purity, a former supermarket brand owned by Woolworths Limited
• Purity, the colorfulness of a light source.