Twenty One Pilots (stylized as twenty one pilots or twenty øne piløts) is an American musical duo from Columbus, Ohio. The band was formed in 2009 by lead vocalist Tyler Joseph along with Nick Thomas and Chris Salih, who left in 2011. The current line-up is Joseph and drummer Josh Dun.

They put out two self-released albums, Twenty One Pilots in 2009 and Regional at Best in 2011, before being signed by Fueled by Ramen in 2012. Their label debut, Vessel, was released in 2013. The duo achieved breakthrough success with their fourth album, Blurryface (2015), which produced the successful singles "Stressed Out" and "Ride". In addition, the single "Heathens", recorded for the soundtrack of the film Suicide Squad, made the group the first alternative artist to have two concurrent top ten singles in the United States. The duo's fifth studio album, Trench, was released on October 5, 2018. They have won a Grammy Award for Best Pop Duo/Group Performance.

Tyler Joseph first met future bandmate Nicholas "Nick" Thomas at a young age while playing youth basketball in Columbus, Ohio. Thomas later transferred to Joseph's middle school, and the two would remain friends through high school.

Joseph began playing music after finding an old keyboard in his closet, a Christmas gift from his mother, and started mimicking radio melodies. In 2007, Joseph recorded a solo album titled No Phun Intended in his parent's basement. Thomas contributed guitar to several songs on the album, and collaborated on the track "Trees", which would later become a signature Twenty One Pilots song.

While attending Ohio State University, Joseph met Texas-born future bandmate Christopher "Chris" Salih at a party. Noting the songwriter's talent and creative energy, Salih consulted Joseph about starting a band. Impressed by the recording studio Salih had built in his house, Joseph agreed to play music together and began sharing his ideas for new music. Just before their first performance, Joseph invited Thomas to the unnamed band as a bassist. In 2009, the group moved into a house of their own, where their first album was conceptualized and recorded in the basement.

The band initially played for a wide variety of audiences at clubs and venues around the Columbus area. Playing at metal, hardcore, and electronic venues influenced Joseph to incorporate these disparate styles with his songwriting. To catch the attention of unfamiliar or disinterested attendees and promoters, the band began to experiment with costumes and on-stage acrobatics.