The event was conceived by race promoter and former Bathurst 1000 competitor Vincent Tesoriero, who in 1990 identified an opportunity to stage a 12-hour endurance race for series production cars at Mount Panorama. Inspired by the original spirit of the Bathurst 500 — the predecessor of the Bathurst 1000 that began in 1960 as a race for standard production cars — Tesoriero secured James Hardie, a long-time Bathurst 1000 sponsor, to back the inaugural event.
The first race took place over Easter 1991 with twenty-four entries spread across six classes defined by engine capacity and specification. Originally planned to run from 9am to 9pm, Bathurst Regional Council restrictions forced a dawn-to-dusk 5:15am start. Despite the unusual hours, twenty cars finished. The race was won by Allan Grice, Peter Fitzgerald and Nigel Arkell in a Toyota Supra.
Manufacturer involvement grew quickly. In 1992, factory-backed teams from Mazda, Holden, Citroën and Peugeot appeared, with Porsche adding factory support from 1993. The Mazda RX-7 proved dominant, winning three consecutive races at Mount Panorama. Rising costs forced the 1995 race to move to Eastern Creek Raceway in Sydney before the event was abandoned entirely in 1996.
A brief revival in 2002 and 2003 under the Bathurst 24 Hour banner, run by PROCAR and dominated by Garry Rogers Motorsport's Holden Monaro 427Cs, proved short-lived due to financial pressures.
The Bathurst 12 Hour returned properly in 2007 as part of the Bathurst Motorsport Festival, again primarily for production cars. Thirty-two cars entered the inaugural modern edition, won by Garry Holt, Paul Morris and Craig Baird in a BMW 335i. BMW and Mitsubishi became the dominant forces across the production car revival period. Mitsubishi Lancers won in 2008 and 2009, with Rod Salmon and Damien White featuring in both winning line-ups. Holt, Morris and John Bowe repeated the 2007 victory in 2010, a race interrupted for an hour when a tree fell across Conrod Straight. Entry numbers grew steadily, peaking at 48 in 2009.
In 2011 GT3-specification cars were admitted for the first time, though initially at the cost of reduced entries as production car teams departed. Joest Racing dominated the 2011 running with two Audi R8 LMS GT3s finishing first and second. Phoenix Racing, a DTM and FIA GT1 outfit, won for Audi again in 2012.
Entry numbers recovered strongly in 2013, with a record field of over fifty cars and the first hour simultaneously counting as the opening round of the Australian GT Championship. Erebus Motorsport took the first win for an Australian team under GT regulations, with Bernd Schneider, Thomas Jäger and Alexander Roloff sharing a Mercedes-Benz SLS AMG.
Maranello Motorsport's 2014 victory carried emotional weight: the team had lost former driver Allan Simonsen in a crash at the 2013 24 Hours of Le Mans, and his memory was honoured by the simultaneous introduction of the Allan Simonsen Pole Position Trophy for the fastest qualifier. Craig Lowndes drove the winning Ferrari to hold off Maximilian Buhk. In 2015 Katsumasa Chiyo brought a Nissan GT-R to victory — Nissan's first major Bathurst triumph since the 1992 Bathurst 1000.
From 2016 the Bathurst 12 Hour became the inaugural event of the Intercontinental GT Challenge, organised by the Stéphane Ratel Organisation and initially including the Sepang 12 Hours and Spa 24 Hours. Shane van Gisbergen qualified quickest and dominated the 2016 race, winning in a McLaren 650S GT3 alongside Álvaro Parente and Jonathon Webb for Tekno Autosports.
Maranello Motorsport repeated their Bathurst win in 2017, with Toni Vilander, Craig Lowndes and Jamie Whincup sharing a Ferrari to receive the Australian Tourist Trophy, which became the event's perpetual outright prize. The 2017 event attracted 55 entries, the highest in the modern revival.
The 2018 race ended early after a major crash at Sulman Park involving Ash Walsh, Bryce Fullwood and John Martin; Robin Frijns, Stuart Leonard and Dries Vanthoor took the flag for Audi Sport Team WRT under a red flag. A record-distance race in 2019 saw Matt Campbell complete three overtakes in the closing stages to deliver Porsche's first victory, alongside Dennis Olsen and Dirk Werner. Bentley broke through for their first Bathurst 12 Hour win in 2020, again breaking the distance record, with Kenny Habul's SunEnergy1 Racing team securing victory.
The 2021 race was cancelled due to international travel restrictions imposed by the COVID-19 pandemic. The 2022 edition was delayed from February to May, with regulation changes including the removal of the all-professional class for the first time since 2016. Twenty cars competed across a damp, fog-affected autumn event. Habul led his SunEnergy1 team to a second victory, with Jules Gounon becoming the second driver to win the race in consecutive runnings having shared the Bentley win in 2020.
The Bathurst 12 Hour transformed from a niche production car novelty into one of the most prestigious GT endurance races in the world. Its inclusion in the Intercontinental GT Challenge elevated Mount Panorama to global GT relevance, drawing factory entries and star drivers from Europe, Japan and the Americas to the demanding mountain circuit. Sponsorship from Liqui-Moly across the 2013–2023 period gave the event its most recognisable modern identity. The Allan Simonsen Pole Position Trophy, awarded annually since 2014, adds a further layer of meaning to what has become the showpiece event of the Australian motorsport calendar's opening weeks.