Australian Channel 10 correspondent Jonathan Lea has told Daybreak that British backpacker Sam Woodhead was found after the search was widened, following sightings of footprints in the sand.
Additional helicopters were called in to find the 18-year-old, who would have been surviving in temperatures of 39 degrees Celsius, in the Australian outback.
Sam Woodhead will be taken to Longreach Base Hospital for a medical assessment, Queensland Police said.
The teenager's sister wrote on Facebook: "We have been told that they have found Sam!! We have no information on his condition or where he was found yet, so keep your fingers crossed."
Sister's plea for info on teen missing in Australian outback
Sam Woodhead. Credit: Family handout.
The sister of a back-packer who has gone missing in Australia has issued an anxious plea for news on Facebook.
Rebecca Woodhead urged people to contact her "ASAP" if they heard anything from her brother Sam.
She wrote: "If anyone hears from my brother please contact me ASAP".
In another posting, she added: "Thanks so much for all your messages regarding Sam.
"Still no further news but we have the helicopter going out again in the morning, Aus time, and hundreds of people going on a voluntary search party. will keep you all posted."
Sam Woodhead, who is 18-years-old and reportedly from Richmond Upon Thames in Surrey, disappeared on Tuesday afternoon after failing to return from a run.
His mother is understood to have urged police to widen the search on the grounds that her son, an experienced long-distance runner, could have travelled some way from his base, near the town of Longreach.
'British backpacker' missing in Australian outback
Police have launched a land and air search for a British backpacker missing in the Australian outback after he failed to return after going for a run.
The 18-year-old male, named by local media as Sam Woodhead from London, left the cattle station where he was staying at 5.30pm on Tuesday, but was not found to be missing until Wednesday morning.
Described as a "health and fitness fanatic", Queensland Police fear the teenager may have become disorientated while running in unfamiliar territory as temperatures reached 39C in the daytime.
His backpack and running shoes were missing from his room but his other belongings, including his wallet, were still there, police said.