''Hybrid Theory'' is the debut album by American rock band Linkin Park, released on October 24, 2000 through Warner Bros. Records. The album was a huge commercial success, having sold over 9.6 million units in the United States alone as of 2009 and peaking at number two on the Billboard 200 while also reaching high positions on other charts worldwide, despite receiving mixed reviews from publications. It has also sold 24 million copies worldwide as of 2009 which makes it the band's best-selling album, the second best-selling album of the decade, behind The Beatles' ''1'', and the twenty-sixth best-selling album of all time.
Recorded at NRG Recordings in North Hollywood, California, and produced by Don Gilmore, the album's lyrical themes deal with problems lead vocalist Chester Bennington experienced during his adolescence, including drug abuse and the constant fighting and divorce of his parents. ''Hybrid Theory'' takes its title from the previous name of the band.
Four singles were released from the album: "One Step Closer", "Papercut", the Grammy Award-winning "Crawling" and "In the End", the latter which was responsible for launching Linkin Park into mainstream popularity. At the 2002 Grammy Awards, ''Hybrid Theory'' was nominated for Best Rock Album. The album is listed in the book ''1001 Albums You Must Hear Before You Die''. It was ranked #11 on ''Billboards ''Hot 200 Albums of the Decade''. A special edition of ''Hybrid Theory'' was released March, 11, 2002, two years after its original pressing.