John Ridley (26 May 1806 – 25 November 1887) was an English miller, inventor, landowner, investor, farming machinery manufacturer, farmer and preacher who lived in Australia between 1839 and 1853.

[4][5] After his mother's death in 1835, Ridley married Mary Pybus, and in November 1839 sailed for South Australia aboard the Warrior with his wife and two infant children,[4][5] arriving in Adelaide on 17 April 1840.

Foreseeing that the heavy spending by governor George Gawler would lead to depression and increased rural production, Ridley let his farm and devoted his time to seeking grain for his mill, purchasing land, and investing in the developing copper-mine at Burra.

Ridley gave much time to the problem of devising a mechanical method of harvesting the wheat and building a reaper based on a woodcut in John Claudius Loudon's An Encyclopaedia of Agriculture (3rd ed., London, 1835).

[7] Although Ridley's returns from the harvesting machine were substantial, they were meagre compared with the dividends from his original shares in the Burra copper-mine, his flour-mill and his land investments.

At his own cost he had printed tens of thousands of copies of sermons and tracts that appealed to his principles and distributed them widely to grateful and ungrateful recipients.

In 1844 he was awarded a special prize by the Agricultural and Horticultural Society and in 1858 he was thanked by the South Australian parliament for a service that had helped to make possible the vast increase of wheat-growing in the province.

Supported by influential friends and by mechanics who had made the original harvesting machine, Bull petitioned parliament in 1880 for a grant in recognition of his invention.

Ridley, a man of the great probity, denied this, and his denial is borne out by the fact that his machine had had two successful trials within two months of the models being exhibited.

[5] Bull devised an idea for a machine based on the comb and beater principle which reaped and threshed on his Mount Barker farm in 1842.

He had the assistance of his good friend, brother-in-law and respected colonist Thomas Hudson Beare to create a working model for exhibition at the Corn Exchange committee meeting in 1843.

Further, these engineering factors, taken together with some additional historical evidence recently brought forward, now enable us to see that Ridley was unjustly accused, and that in fact he is fully entitled to the credit for the "stripper's" invention as well as for its introduction.