The incident happened at the Novotel Queenstown hotel, in Marine Parade, about 2.10pm.
The girl appeared to have fallen about 4m from a first-floor balcony and landed on grass next to some concrete.
Otago Rescue Helicopter Trust intensive care paramedic Doug Flett confirmed the girl has been flown to Christchurch Hospital.
"She was initially taken to Lakes District Hospital and assessed.
"They opted to transfer her and asked for us to provide an ICU [intensive care unit] level transfer," Mr Flett said.
"She was in a moderate to serious condition."
No further information about her condition was available.
Jose Lacambra, of Argentina, who saw the girl fall, said she was fortunate to land on grass outside the hotel, rather than concrete.
"She nearly fell on the concrete, but was very lucky.
"I heard her mother screaming. We went over and were holding people back. It was a little girl. She was crying a lot - crying a lot."
Another person, who declined to be named, said the girl was about 5 years old and seemed to be OK after the fall.
"She was OK. Nothing broken, I don't think.
"She was in her mother's arms. A good result, really."
Two tourists have died falling from Queenstown balconies in the past five years. Both were young men who fell at night after drinking alcohol.
Jo Finnigan, general manager of Novotel Queenstown's sister hotel Hotel St Moritz, released a statement on Saturday on behalf of the Accor group.
"We are saddened that a child was injured in a fall at the Novotel Queenstown earlier today.
"Our thoughts are with the child and their family at this difficult time, and with those who witnessed the incident.
"We appreciate all the efforts made by the hotel team and the emergency services who responded. We also extend our sincere thanks to members of the public who were nearby for their assistance."
