1000 Forms of Fear is the sixth studio album by Australian singer Sia. It was released on 4 July 2014 by Monkey Puzzle and RCA Records worldwide, and Inertia Records in Australia. Primarily an electropop album, the record also incorporates influences from reggae and hip hop. Lyrically, the record is focused on Sia struggling to deal with drug addiction and a diagnosis of bipolar disorder at the time, rediagnosed as complex PTSD in 2019.
 
1000 Forms of Fear received generally favorable reviews from music critics, who praised Sia's vocals as well as the album's lyrical content. The album debuted at number one on the US Billboard 200 with first-week sales of 52,000 copies. The release also charted atop the charts of Australia and Canada, and reached the top five charts of Denmark, New Zealand, Norway, Sweden, Switzerland, and the United Kingdom. As of 26 October 2015, it has been certified gold by the RIAA denoting 500,000 equivalent-album units sold in the United States. As of January 2016, the album has sold 1 million copies worldwide.
 
The album spawned four singles. Its lead single, "Chandelier", released in March 2014, became a worldwide top-10 single; it also peaked at number eight on the US Billboard Hot 100, becoming the first song by Sia to enter the chart as a lead artist. "Big Girls Cry" was released in June 2014. Sia's solo version of "Elastic Heart", which was originally a collaboration with The Weeknd and Diplo, was released in January 2015, and reached the top 20 of the Hot 100. "Fire Meet Gasoline" was released as the fourth and final single in Germany on 19 June 2015. The official music video for "Chandelier" has been viewed on YouTube more than 2 billion times, and the video for "Elastic Heart" has been viewed more than 1 billion times.
 
1000 Forms of Fear debuted atop the US Billboard 200 with first-week sales of 52,000 copies. By doing so, it became the lowest sales figure for a number-one album on the chart in nearly two years. The Guardian's Clem Bastow commented on the album's success in the United States: "Australian artists typically fare better in the Billboard Hot 100 singles chart, but even then, Sia finds herself in rarefied company." On behalf of The Sydney Morning Herald, George Palathingal opined that the album's debuting atop the Billboard 200 is the result of "a stroke of (anti-)marketing genius" and "a case of quality pop music standing proud." 1000 Forms of Fear had sold 374,000 copies in the United States as of December 2015.