String theory is a branch of theoretical physics.

String theory may also refer to:

• Concatenation theory, a topic in symbolic logic dealing with strings of characters

Music

• String Theory (band), an American electronic music band
• String Theory (Hanson album), 2018
• String Theory (The Selecter album), 2013

Other media

• "String Theory" (Heroes), retitled "Five Years Gone", an episode of the TV series Heroes
• "String Theory" (The Shield), an episode of the TV series The Shield
• String Theory (novels), a trilogy of Star Trek: Voyager novels
• String Theory, a webcomic graphic novel based on the TV series Heroes
• String Theory (artist collective), based in Gothenburg, Sweden, and Berlin, Germany

• String theory landscape, the large number of possible false vacua in string theory
• Knot theory, a branch of mathematical topology