"Bad Guy" is a song recorded by American singer-songwriter Billie Eilish. Darkroom and Interscope Records released it as the fifth single from her debut studio album When We All Fall Asleep, Where Do We Go? on March 29, 2019.
Eilish and her brother Finneas O'Connell co-wrote "Bad Guy", with the latter also producing it. The song was described as pop-trap and nu-goth pop in press reviews, for which synth bass, a kick drum, finger snaps and 808 bass provide minimalist instrumentation. During the song's lyrics, Eilish taunts her lover for being a bad guy although suggesting that she is more resilient than he is.
Upon its release, "Bad Guy" mainly received positive reviews from music critics, several of whom praised its lyrics. It was also likened to music recorded by the White Stripes, Lorde and Fiona Apple.
"Bad Guy" was a commercial success, reaching number one on the US Billboard Hot 100, as well as on the charts in Australia, Canada, Estonia, Finland, Greece, Iceland, New Zealand, Norway and Russia. In the United States, "Bad Guy" ended the record-breaking 19-week run of "Old Town Road" by Lil Nas X featuring Billy Ray Cyrus.
"Bad Guy" also peaked at number two on the UK Singles Chart, among others. It has been awarded several certifications, most notably a quadruple platinum award from the Australian Recording Industry Association (ARIA) and Music Canada.
Dave Meyers directed the music video for "Bad Guy" which was uploaded onto Eilish's YouTube channel at the same time as the single's digital release. The video depicts Eilish being involved in several activities, including wild dancing, suffering a nosebleed and sitting on the back of a man doing push-ups. Reviewers noted the video for its camp elements and eccentric imagery.
Eilish promoted the song by performing it live at venues including Coachella Valley Music and Arts Festival, Glastonbury Festival and during her 2019 When We All Fall Asleep Tour.