The woman, whose name was not reported, said she was sitting on her porch when her toddler chased a ball into their neighbor's yard Monday evening, The Cairns Post reported.
"Then I heard this blood curdling scream," she said. "The snake was biting his leg and was wrapped around his whole body, to his chest. It started constricting."
The woman was not able to pull the snake off the boy by herself, but her screams alerted neighbors, who then called authorities.
An ambulance transported the toddler to a hospital where his wounds were treated.
A Queensland Health spokesman said the boy had four snake bite wounds from a non-venomous scrub python.
The boy was released from the hospital after 24 hours.
Marlin Coast Veterinary Hospital veterinarian Rod Gilbert said the python may have confused the boy for a wallaby.
"I suppose a 2-year-old boy is not much different from a wallaby -- it could definitely happen," Gilbert said.