Proof could mean:

• An argument, including:
  • Mathematical proof
  • Proof theory, a branch of mathematical logic
  • Logical argument
  • Evidence (law), tested evidence or a legal proof
• Proof (alcohol), measure of an alcoholic beverage's strength
• Proofing (baking technique), how a yeast-leavened dough rises
• Proofreading
• Artist's proof, a single print taken during the printmaking process
• Proof coinage, a coin made as an example of a particular strike
• Proof test, for a firearm
• Galley proof, an early version of a publication
• Homeopathic proving, testing a substance's effect on the body

In entertainment:

• Proof (1991 movie), an Australian movie by Jocelyn Moorhouse
• Proof (play), a play by David Auburn
• Proof (2005 movie), a movie directed by John Madden, based on the play
• "Proof", a song by Paul Simon from his 1990 album The Rhythm of the Saints
• Proof (rapper) (1973-2006), American rapper, a member of the group D12