"Bad Liar" is a song by American singer Selena Gomez, released on May 18, 2017 by Interscope Records. The track was written by Gomez, Julia Michaels, Justin Tranter, and its producer Ian Kirkpatrick. The song samples the bassline from Talking Heads' 1977 single "Psycho Killer", written by David Byrne, Chris Frantz and Tina Weymouth. A vertical music video accompanied the release, becoming the first music video to premiere on Spotify, where it was made available exclusively. The official music video directed by Jesse Peretz, was released on June 14, 2017 on Gomez's Vevo channel on YouTube, in which she portrays four characters.
"Bad Liar" received universal acclaim from music critics; Billboard ranked it as the best song of 2017. Critics noted the mid-tempo production for its non-traditional structure in Gomez's catalog. David Byrne, Talking Heads' lead singer, also complimented the song. Commercially, the song reached the top 20 in Australia, Canada, the Czech Republic, Finland, Hungary, Lebanon, Malaysia, Mexico, New Zealand, Slovakia, and the United States; as well as the top 40 in Austria, Denmark, France, Germany, Ireland, Norway, Portugal, Sweden, Switzerland, and the United Kingdom. In 2019, Rolling Stone ranked "Bad Liar" at number 39 on its list of best songs of the 2010s.