Defqon.1 （Dutch multi-electronic-style series of compilation albums based on the Defqon.1 festivals organized by Q-Dance BV.）

Defqon.1 Festival is an annual music festival held in the Netherlands and Australia. It was founded in 2003 by festival organizer Q-dance. The festival plays mostly hardstyle and related genres such as hardcore techno, jumpstyle and hard trance.

The festival was previously held in mid-June on Almeerderstrand in Almere. Since 2011 it is hosted on the event site next to Walibi Holland in Biddinghuizen. Since 2009 the event has also been hosted in Sydney in mid-September, at the Sydney International Regatta Centre. The festival runs for 12 hours, from 11 a.m to 11 p.m, and ends with a firework display. Each edition also has an anthem, an official song that is played in conjunction with the festival.