Diamond Rings is the musical alter-ego of Toronto-based multiplatform artist John O (John O'Regan), first conceived in the summer of 2009. A 7" and home-made video for his first bedroom-recorded single "All Yr Songs" helped to propel Diamond Rings into the spotlight, first garnering attention from Canadian blogs like Chromewaves, and then eventually a "Best New Music" honors from Pitchfork. The 7" was issued as split with fellow Ontario musicians PS I Love You on O'Regan's own boutique label, Hype Lighter.

Diamond Rings followed suit in 2010 with two more vinyl singles and corresponding videos: a 7" for the song "Wait & See" on German-based label Tomlab in February, and a 12" single for "Show Me Your Stuff" as the first-ever release on Toronto-based One Big Silence.

Diamond Rings signed to Montreal-based Secret City Records in mid-2010 and issued a fourth vinyl single/video for the song "Something Else" in September 2010, in advance of his debut-full length Special Affections. In addition to "Something Else" Special Affections includes the previous singles "All Yr Songs" and "Wait & See," and was released in North America on October 25, 2010 by Secret City.

His second full length album, Free Dimensional, was released on 23 October, 2012.