Ieperfest is a Belgian hardcore music festival held in Ypres (Dutch: Ieper). The summer edition of the festival was first held in September 1992, then annually each August from 1994 to 2018 (no summer event was held in 1993). Since 2019, the summer edition has been held annually each July. In February 2008, a winter edition was introduced, which was held annually in either February or March, until 2015 (no winter event was held in 2009). The winter edition has since been held sporadically, namely in 2018 and 2022. In 2012, during its 20th anniversary, Ieperfest became the longest-running hardcore festival in the world.

From 1992 to 1998, the festival was held inside De Vort'n Vis concert venue in Ypres; but starting with the 1999 edition, outdoor locations have been used to accommodate a growing audience. The 1999 and 2000 editions were held in the open courtyard of the Stedelijke Academie voor Muziek en Woord music school. From 2001 to 2007, the festival was held at the Jeugdstadion Camping Site parking lot (with the exception of 2002 when it was held on the grounds of the CID Lines company). In 2008, Ieperfest moved to its current open air location on Poperingseweg.

The festival was first organized by Edward Verhaeghe, owner of the record label Warehouse Records (now Good Life Recordings), in September 1992. Verhaeghe has had little involvement in the booking of the festival following its first year. Hans Verbeke, owner of Sober Mind Records and an employee at De Vort'n Vis, took over for the 1994 and 1995 editions, until Bruno Vandevyvere, owner of Genet Records and Pyrrhus Records and an owner of De Vort'n Vis, became the main organizer in 1996; a position he continues to hold.

Though Ieperfest has historically focused on metalcore bands, a wide variety of hardcore and metal groups have also performed throughout its span, including emotional hardcore, post-hardcore, punk rock, grindcore, death metal, thrash metal, sludge metal, doom metal and stoner rock. The festival has been singled out as influential to Michal Kočan, who cited it as his motivator to start his own Czech music festival, Fluff Fest.

Ieperfest was first conceived in 1992 by Belgian vocalist Edward Verhaeghe, a hardcore musician who had played in such bands as The Midnight Men, Rise Above and Nations on Fire, and was then operating the record label Warehouse Records. Verhaeghe would later establish the noted Belgian hardcore record label Good Life Recordings.

Although Verhaeghe resided in Kortrijk, Belgium, he booked his new festival at De Vort'n Vis, a popular concert venue for hardcore bands located 30 minutes away in Ypres, Belgium. The festival was not booked again in 1993.

In 1994, another noted Kortrijk, Belgium-based musician, Hans Verbeke, took over the booking of the festival. Verbeke worked at De Vort'n Vis, and had played in such bands as Rise Above, Shortsight, Blindfold, Spirit of Youth, Wheel of Progress (and later Liar) and was also operating the hardcore record label Sober Mind Records. Verbeke also booked the 1995 edition.

In 1996, the festival was taken over by Ghent, Belgium-based Bruno Vandevyvere, owner of the record label Genet Records and the record store Pyrrhus Records. Vandevyvere was one of the founders of De Vort'n Vis and had therefore been involved in the first three editions' bookings to some extent. In 1999, Genet Records released the compact disc Various Artists compilation Vort'n Vis Hardcore Festival 1998, which documented most of the bands that had performed at the 1998 edition of the festival.