Harwood sugar mill is located on the Clarence River north of Grafton in New South Wales.

Colonial Sugar Refinery commenced sugar operations on the Clarence River in 1870. In 1873 they moved the Darkwater mill from the Macleay to the present day Harwood Island site.

Harwood mill then commenced operations in 1874 and remains the oldest operating mill in Australia.

The first crop was 25,550 ton of cane and the crushing rate was 10 ton per hour.