Which DJ led the Disco Demolition Night promotion in Chicago?

The DJ who led the Disco Demolition Night promotion in Chicago was Steve Dahl.

Dahl was a Chicago radio personality whose station had switched from rock to disco and dismissed him in late 1978. He and fellow broadcaster Garry Meier began mocking disco on the air, and the campaign evolved into a promotional event with White Sox organizers and WLUP staff. Dahl became the public face and host of the promotion.

Disco Demolition Night took place at Comiskey Park on July 12, 1979, during a White Sox doubleheader. Fans could obtain admission by bringing a disco record and 98 cents, a reference to WLUP’s 98.0 frequency. Collected records were piled in center field and detonated between games.

The event escalated when thousands of attendees entered the field, causing fires, property damage and disorder. The second game was forfeited to the visiting Detroit Tigers, and the incident became one of the most notorious episodes of the late-1970s disco backlash. Dahl is the canonical answer, although the event involved several co-organizers, including Garry Meier, Mike Veeck and WLUP personnel.