Michael Trent Reznor (born May 17, 1965) is an American musician, singer, songwriter, record producer, and composer. He came to prominence as the founder, lead vocalist, multi-instrumentalist, and primary songwriter of the industrial rock band Nine Inch Nails. The band's line-up has constantly changed, with Reznor being its only official member from its creation in 1988 until 2016, when he added English musician and frequent collaborator Atticus Ross as its second permanent member.

Reznor began his career in 1982 as a member of synth-pop bands such as The Innocent and Exotic Birds. The first Nine Inch Nails album, Pretty Hate Machine (1989), was a moderate success but largely remained popular with underground audiences; the next two albums, The Downward Spiral (1994) and The Fragile (1999), brought the band widespread critical acclaim. There have since been eight more Nine Inch Nails albums and six EPs. Reznor has also contributed to the work of artists such as his protégé Marilyn Manson, rapper Saul Williams, and pop singer Halsey. Alongside his wife Mariqueen Maandig and long-time collaborators Atticus Ross and Rob Sheridan, he formed the post-industrial group How to Destroy Angels in 2009.

Beginning in 2010, Reznor and Ross began to work on film and television scores. The duo have scored many of David Fincher's films, including The Social Network (2010), The Girl with the Dragon Tattoo (2011), Gone Girl (2014), Mank (2020), and The Killer (2023). They won the Academy Award for Best Original Score and the Grammy Award for Best Score Soundtrack for Visual Media for both The Social Network and Soul (2020). They won the Primetime Emmy Award for Outstanding Music Composition for a Limited Series for Watchmen (2019). Reznor, Ross, Dave Sitek, and Hudson Mohawke created the virtual supergroup WitchGang in 2023. As Nine Inch Nails, they are creating the soundtrack to Tron: Ares, to be released in 2025.

In 1997, Reznor appeared on Time's list of the year's most influential people and Spin magazine described him as "the most vital artist in music"..