Kanza Rehman, 21, understood to be from Aberdeen, has been left seriously injured after the fall from the second floor of the building in San Antonio.
Police are investigating the incident.
Miss Rehman was taken to Can Misses Hospital near the capital Ibiza Town after being stabilised at the scene.
She is expected to be transferred to Son Espases Hospital in Majorca because of the severity of her condition.
It has been reported that a man she was with has been interviewed in relation to the incident, but it is claimed it has been a tragic accident and he witnessed her falling over the balcony.
The apartment is understood to be privately-owned.
Thousands of people flocked to Ibiza this Bank Holiday weekend.
Kanza is reported to be from Aberdeen and studying International Tourism Management at Robert Gordon University.