The humpback whale, believed to be two years old, was successfully fitted with a specially designed harness and a boat was used to tow it into deeper waters.
It was the fifth attempt at removing the whale since it washed up on Palm Beach in Queensland State late on Tuesday.
In previous attempts, the rope linked to the harness snapped or the whale got stuck on a sandbar slightly further offshore.
"We were working against the conditions, time was running out on us", Tacha Mulligan, the marine animal supervisor at Queensland's Sea World marine park, told the Australian Broadcasting Corporation.
"It was the perfect time to go when we were able to release it. We are cautiously optimistic it will be okay from here on in."
Rescuers had erected marquees to keep the whale cool during the day, while staff from Sea World and Queensland's department of environment and heritage protection cared for it at night.
Mulligan said the whale would be exhausted after being out of the sea for many hours.
"It's been through quite an ordeal", she said, adding that the animal was now in deep water and rescuers would monitor its progress through the day.
Whale beaching are relatively common in Australia, but scientists do not know why they happen.
Humpbacks are currently on their annual southern migration from Antarctica to warmer waters in Queensland State to give birth and mate.