Flex is the second studio album by American singer-songwriter Lene Lovich, released in 1979 by Stiff Records. The album is produced by Lovich and Les Chappell with additional production by Roger Bechirian and Alan Winstanley. It was recorded at the Wisseloord Studios in Hilversum, Netherlands. She worked with Chappell and Judge Smith on writing the songs.
The cover sleeve depicts Lovich wearing a wedding dress and playing with hockey pucks on a string. It was taken inside a stainless steel fermentation tank at a Guinness brewery, after it had been emptied prior to cleaning. It caused controversy and few members of the Baptist church tried to get the album banned in the United States, saying it depicted an act of witchcraft.
Lovich described Flex as her more introverted album. After its release, it received relatively positive reviews praising album's enhanced production compared to her previous album Stateless' rough sound. It was also more successful in charts, peaking at number 94 on the Billboard 200 and number 19 on the UK Albums Chart. The lead single "Bird Song" peaked at number 39 on on the UK Singles Chart. The following singles were "Angels" and "What Will I Do Without You?", of which the latter peaked at number 58.
The release of the album was followed by Lovich's first sold-out tour in the United States and a three-month tour within Europe, the highlight of which was a sold-out show in front of 10,000 fans in Belgrade.