The man, 24, believed to be from Manchester, fell over 20ft from the balcony in the resort town on the Spanish island of Majorca.
The holidaymaker — who hasn't been named — was rushed to hospital in the Majorcan capital Palma after falling at around 5am Saturday morning.
Police said: "He fell around 22 feet from a second-floor balcony in circumstances which are still being investigated."
Yesterday's accident happened at the Nova Apartments, close to Punta Ballena in the heart of Magaluf.
An emergency services worker said: "The alarm was raised a few minutes after 6am on Saturday.
"The injured man was taken to Son Espases Hospital in the Majorcan capital Palma."
The Brit is believed to have been drinking before his fall. The full extent of his injuries isn't yet known.