The Halo 4 Original Soundtrack is the official soundtrack to the first-person shooter video game Halo 4, developed by 343 Industries and published by Microsoft Studios. British record producer Neil Davidge was Halo 4's main composer and producer. The soundtrack was released on October 19, 2012 in Australia and New Zealand, and October 22 everywhere else. A second volume containing more of the score was released digitally on April 8, 2013.

Davidge was a Halo fan who was honored to have the chance to write music for the games. Drawing inspiration from the game's concept art and other visuals, he began writing music for the game in December 2010. Davidge described his music as an evolution of previous Halo music, designed to accompany the new style of the universe.

Critical reception to Halo 4's music and the soundtrack was highly positive. However, its stylistic departure from earlier Halo music composed by Martin O'Donnell was divisive. The album debuted the No. 50 on the Billboard 200 chart in the United States, making it the highest-charting game soundtrack ever.

The majority of previous Halo soundtracks had been composed by Martin O'Donnell, Michael Salvatori, and the Bungie audio team; Stephen Rippy composed the music for the spinoff game Halo Wars. Davidge is best known for his work as a co-writer and producer for Massive Attack, and has also composed the scores for a number of films.

Halo 4 audio director Sotaro Tojima began looking for the game's composer in 2010. "I had a vision for the overall Halo 4 music production that I think of as 'Digital and Organic'," he wrote—"something very much inspired by the game script." This vision led him to explore electronica and dance music to find his chosen sound. Tojima decided on Davidge after a year's search. 343 Industries officially named Davidge as Halo 4's main composer on April 11, 2012; by that point the name of Halo 4's composer had been kept a secret for fifteen months.

Davidge is a longtime Halo fan; he would play Combat Evolved during downtime while producing Massive Attack albums in 2001. Davidge credits the games with providing a heroic story that reminded him of his youth reading comic books. "I'd love to be able to inspire people [like Halo does]," he said. Davidge flew to Seattle, Washington in December 2010 to meet 343 Industries personnel. Afterwards he began writing concept and prototype music for the project before being officially engaged in July or August 2011.

Davidge initially thought that scoring the video game would be similar to the process for a film; "Pretty soon I discovered the similarities were few," he later told Rolling Stone, since music for the game had to dynamically change its length and composition depending on player actions. Much of Halo 4's music was written on guitar or piano; at home, Davidge would sometimes sing melodies into a dictaphone for later transcription. While composing, he viewed slideshow images and visual material to influence his work. Davidge played through unfinished portions of the game for inspiration; he ended up using the game's development concept art as inspiration for his music.

While Davidge professed himself as a huge fan of O'Donnell's work, he felt the music needed to change to fit the new trilogy. "The phrase that kept going around was 'evolution not revolution' of the score," he said. "[They wanted a] more electronic, slightly more beat-driven direction, which is one reason why they came to me. They wanted to flesh out, sonically, a new universe. One that they could expand on in subsequent sequels.”