Metanoia, an Ancient Greek word (μετάνοια) meaning "changing one's mind", may refer to:

• Metanoia (psychology), the process of experiencing a psychotic "breakdown" and subsequent, positive psychological re-building or "healing"
• Metanoia (rhetoric), correction, a rhetorical device
• Metanoia (theology), "conversion" and "reformation" or repentance
• Metanoia Films, a film production company
• Metanoia, a word for the act of prostration in Christianity
• Metanoia, a direct climbing route opened in 1991 by Jeff Lowe on the Eiger's north face
• Metanoia: A Speculative Ontology of Language, Thinking, and the Brain, the 2019 book by Armen Avanessian and Anke Hennig

• Metanoia (Australian band), a Christian metal band
• Metanoia (Chilean band), a Christian hardcore band
• Metanoia (For All Eternity album), 2015
• Metanoia (IAMX album), 2015
• Metanoia (Porcupine Tree album), 1998
• Metanoia (Yōsei Teikoku album), 2007
• Metanoia (Persefone album), 2022
• Metanoia, Pt.1, an album by Druha Rika, 2012
• "Metanoia" (song), by MGMT, 2008
• "Metanoia", a song by Gerry Rafferty from Another World, 2000
• "Metanoia", a song by The Human Abstract from Midheaven, 2008
• "Metanoia", a song by King Missile from Happy Hour, 1992
• "Metanoia", a song by Japanese artist Nana Mizuki, 2019

• Metania, a form of bowing in the Eastern Orthodox Church