To Mega Therion (, ) may refer to:
- The Beast (Revelation), one of three beasts described in the Book of Revelation
- Aleister Crowley (1875–1947), also known as To Mega Therion, English occultist
- Therion (band), formerly named Megatherion, a Swedish symphonic metal band
- "To Mega Therion", a song by Therion from the 1996 album Theli
- To Mega Therion (album), a 1985 album by Celtic Frost
- Tomegatherion, a fictional character in the video game Body Harvest
See also
- Megatherium, an extinct genus of ground sloths
- Therion (disambiguation)