John Campbell Miles (5 May 1883, Richmond, Melbourne – 4 December 1965, Ringwood, Victoria) was an Australian prospector and pastoral worker who discovered the mineralisation upon which the Mount Isa Mines were established in Queensland.
Blainey listed his quick progression of jobs as ploughman, miner, carter, railway navvy, wild-pig hunter and windmill repairer.
At the age of twenty-four (1907) he took a job as underground worker at Broken Hill, but stayed only until the following April before riding his bicycle 1,500 miles to the newly discovered Oaks goldfield (later known as Kidston) in north Queensland.
After a brief visit to Melbourne in 1921, he decided to follow up the reminiscences of an elderly boundary rider who claimed to have seen gold on the Murranji Track, a cattle trail in the Northern Territory.
He travelled slowly with his six horses, camping near to Hughenden and Richmond and visiting the ghost town of Mount Elliott on the Cloncurry copper field.
It was probably characteristic of Miles, whose only admitted vice was pipe-smoking, that he should return to the north-west overland by car, camping under the stars, and then accept accommodation only in the workers' barracks.