Toxicity is a measure of the degree to which something is toxic or poisonous. For related concepts, see:

• Toxin, a substance produced by living cells or organisms
• Toxic mold, a substance produced by some fungi
• Mycotoxin, the excrement of mold

Toxicity may also refer to:

• Toxicity (album), a 2001 album by System of a Down
• "Toxicity" (song), the second single from the System of a Down album

Toxic may refer to:

• Toxic!, a British comic
• Toxic magazine, a British boy's magazine
• Johan "Toxic" Quick, a professional gamer from Sweden
• "Toxic" (song), the Grammy Award-winning single by Britney Spears