The Millennium Mine (also known as the Millennium Complex) is a metallurgical coal operation located 140–160 km south-west of Mackay near Moranbah.

Originally developed by Peabody Energy, the mine commenced production in the mid-2000s as an open-cut operation producing hard coking coal and PCI coal for export to global steelmakers. At its peak, the mine produced several million tonnes of saleable coal annually, supported by truck-and-shovel mining and coal processing infrastructure.

After being placed into care and maintenance in 2020, the operation was acquired and restarted in 2021 by the MetRes joint venture (Stanmore Resources and M Resources), with a shift toward underground mining at the Mavis Downs deposit alongside residual open-cut and highwall extraction. The redevelopment aimed to produce around 1–1.2 million tonnes per year of high-quality metallurgical coal.

However, due to challenging economics and market conditions, the operation has again been placed on care and maintenance as of 2024–2025.