Ice Nine Kills is an American heavy metal band from Boston, Massachusetts. The band's music is primarily described as horror-themed metalcore, but incorporates many other musical styles. It was originally a ska punk band called Ice Nine, formed in 2000 by high school friends Spencer Charnas and Jeremy Schwartz, before adopting a metalcore style in 2010. Charnas is currently the only remaining founding member. The band is signed to Fearless Records.

Ice Nine Kills has released three EPs along with six full-length studio albums: Last Chance to Make Amends, Safe Is Just a Shadow, The Predator Becomes the Prey, Every Trick in the Book, which peaked at number 122 on the US Billboard 200; The Silver Scream, which peaked at number 29; and their latest, The Silver Scream 2: Welcome to Horrorwood which peaked at number 18. Their band name is derived from the fictional substance ice-nine from the 1963 novel Cat's Cradle by Kurt Vonnegut.

In 2025, Jeff Mezydlo of Yardbarker included the band in his list of "the greatest metal acts that formed in the 2000s". In 2023, Jake Richardson of Loudwire included Spencer Charnas in his list of the "10 Best Clean Singers in Metalcore".