Halo may refer to:

• Halo (optical phenomenon), a ring of light that surrounds an object
• Halo (religious iconography), a ring of light that surrounds an object in religious iconography
• Halo (comics), a DC Comics superhero
• Halos, a variation of the Windmill breakdance move
• Halo, West Virginia

• Halo (band), a heavy metal band that started in Australia
• Halo, a song by Depeche Mode in their album Violator
• Halo, a song by Texas in their album White On Blonde
• Halo numbers, an unofficial method of cataloging Nine Inch Nails releases
• Halo, a song by Gary Numan on his album Jagged
• Halo, a Christian Rock band from 1980's and 90's Pakaderm and Word Records

• Halo (medicine), a device to immobilize head and neck after a spine fusion
• Halo effect, a cognitive bias whereby the perception of a particular trait is influenced by the perception of the former traits
• Galactic halo, a region of space surrounding spiral galaxies
• Nuclear halo, a shape exhibited by some exotic atomic nuclei
• Halo vehicle, an automobile marketing strategy
• Halo (visualization technique), a computer interface technique that uses arcs to point users to off-screen locations

• Halo (series), by Bungie Studios
• Halo: Combat Evolved, the first game in the series
• Halo (film), a film based on the series, currently halted in production
• Halo (megastructure), an eponymous ring-shaped space station

• HALO/HAHO (High Altitude, Low Opening/High Altitude High Opening), a form of parachute jump
• BAE HALO (High Altitude Low Observability), a military aircraft under development
• HALO Trust (Hazardous Areas Life-Support Organization), a charity for removing war debris
• Mil Mi-26 a heavy transport helicopter codenamed Halo

• HALO: Hidden Alias List Operation, a witness protection program in the movie Charlie's Angels: Full Throttle.