The two-year-old had to be taken to hospital by helicopter from Brevard Zoo in Melbourne.
Firefighters said the child’s mother was also taken to hospital for treatment.
In a statement, the zoo said the child stumbled and fell between two metal poles separating the family from the zoo’s white rhinoceroses during a hands-on experience.
“At this point, the snout of at least one of the rhinoceroses made contact with the child,” the zoo said.
“Our number one concern is the safety and welfare of our guests and our hearts go out to the family” said Keith Winsten, the zoo’s executive director.
“Safety has always been of paramount importance to us and we are suspending these encounters until we have thoroughly reviewed our processes and procedures to ensure this cannot happen again.”
The zoo has four southern white rhinos.