Farleigh Mill was built in 1883 by Sir John Bennett Laws, founder of the world's oldest agricultural research station at Rothamsted, UK, which is still functioning. The mill originally operated a plantation; however cultivation was suspended after a few years. The mill was sold to the Farleigh Estate Sugar Co Ltd in 1900 and improvements were made to crush cane previously crushed at several other Mackay district mills - Ashburton, The Cedars, Coningsby, Pioneer, Richmond, Nindaroo, Habana and Dumbleton.

In 1921, Farleigh assumed responsibility for crushing cane from the Rosella district, south of the Pioneer River, after the CSR Company discontinued operations at the nearby Homebush Mill. The extra cost and commitments involved in this transaction, together with several poor seasons, forced the company into liquidation in 1926. The mill was then purchased by its growers and operated on a co-operative basis.

In 1927, the Homebush suppliers were transferred to the Racecourse Mill and Farleigh's crops were enhanced by the development of rich scrublands in the Kolijo-Calen district, and other areas to the north served by the state-run North Coast railway. In 1956 construction work began on the mill's own rail line to the north coast areas, due to the need to improve cane transport to cope with the increased throughput and to reduce the constantly-increasing expense of using the government-owned rail line. The line was completed in 1961.

Farleigh Mill growers voted to merge with other Mackay district mills to form the Mackay Sugar Co-operative Association Ltd in November 1987.

Mackay Sugar committed $14 million to extensive upgrading of the Summit section of the rail line in 1997 to eliminate several kilometres of steep grades. The upgraded line is able to cope with increased tonnages and deliver transport cost savings and scheduling flexibility to the mill.

Extensive reconstruction and modernisation of the mill's plant and machinery has been undertaken since the 1940s to increase output and improve efficiency.