Since I Left You is the debut studio album by Australian electronic music group the Avalanches, released on 27 November 2000 by Modular Recordings.

It was produced by group members Robbie Chater and Darren Seltmann (under the pseudonym Bobbydazzler), and samples extensively from various genres.

After the album's positive reception in Australia, the duo considered an international release – its date was held back until 2001 in the United Kingdom and North America and appeared in slightly altered forms.

"[9] The sources span many different styles of music, sampling artists such as Françoise Hardy, Blowfly, Sérgio Mendes, Raekwon, Wayne and Shuster, and Madonna.

[14] In February 2000, Seltmann (as Dazzler) and Chater (as Bobby C) finished production on the album under the pseudonym Bobbydazzler, and its official title was revealed as Since I Left You in March 2000.

[14] When Since I Left You was being recorded, the Avalanches had trouble choosing songs to be released as singles, finding them not sounding as good outside the context of the album.

[14] On 21 August 2000, "Frontier Psychiatrist" was released as the second single from the album by Modular in Australia in both a four-track and two-track version.

[19] To celebrate the album's release in Melbourne, the group had a boat cruise party through Port Phillip Bay.

[16][10] In April, Since I Left You was released in the UK through XL Recordings with the album selling far more copies than the label's original target amount.

[22] The album artwork features an excerpt of Sinking of USS President Lincoln by Fred Dana Marsh (1920).

[25][26] In July 2011, a deluxe reissue of Since I Left You was announced that would include the original album as well as a bonus disc containing b-sides, demo tracks and remixes of songs from the original album by artists including El Guincho, MF DOOM, Black Dice, and the Avalanches themselves.

[30] Later, a finished 4xLP deluxe edition copy made its way into the hands of a collector, who submitted pictures and details about the release to Discogs.

The deluxe edition features alternate artwork and a collection of new remixes from MF DOOM, Deakin, Leon Vynehall, Canyons, Sinkane, Sun Araw, Black Dice, and Edan alongside select previously released remixes, and the original demo of Thank You Caroline.

To promote Since I Left You, the Avalanches organised their first Australian head-lining tour in October 2000, planning to head to all the capital cities.

In their Brisbane show, Seltmann broke his leg in an on-stage collision with bass guitarist and singer Tony Di Blasi.

From January to February 2001, the Avalanches toured with the Big Day Out festival in Australia, visiting four capital cities.

[45] Christian Ward of NME hailed it as "a joyous, kaleidoscopic masterpiece of sun-kissed disco-pop",[35] and Andy Battaglia from The A.V.

[2] Marc Savlov of The Austin Chronicle found the album as surprising as "Primal Scream's life-changing Screamadelica was a decade ago.

[47] Pitchfork's Matt LeMay credited the Avalanches for developing a "unique context" for the songs without compromising their original "distinct flavor" and said that the album "sounds like nothing else" because of how the samples are employed rather than their quality or volume.

[48] Robert Christgau of The Village Voice was less enthusiastic and said that the Avalanches deliver "the long-promised new-songs-from-old-songs trick, in which untrackable samples are stitched together until they mesh into compelling music that never existed before.

"[6] Stylus Magazine's Tyler Martin felt that the tracks lack innovation, nuance, and rhythmic complexity, but that several of them are exceptional.

Since I Left You was included on this list with Chris Johnston declaring the album to be "a beautiful piece of musical art made entirely from samples.

[59] Philip Sherburne, writing for Rhapsody, said that "along with DJ Shadow's Endtroducing, this is one of plunderphonic music's greatest LPs".