The man was trying to get aerial shots of the famous canal city, where drones are banned, but lost control of the mini aircraft, which happened to land close to a group of police officers patrolling the area.
Fortunately, the 2kg drone fell in an area where there were not many people and nobody was hurt.
The unmanned aircraft had been hovering over the Punta della Dogana, on the opposite side of St Mark's Basin, before crossing the canal and crashing in St Mark's Square.
Police were perplexed as to who owned the drone, until the tourist came forward on Tuesday and asked for it back.
The amount he was fined has not been reported, but violating Italian aviation rules is an offence potentially punishable with fines of up to €113,000.
Current guidelines say drones cannot be flown above 230 feet (70 metres) and must remain within a 490 foot (150 metre) radius of the pilot at all times.
Laws also state that drones must carry third-party insurance and that piloted aircraft must not come within 80 meters of private property. Crucially, they cannot be flown over populated areas or railways, factories and roads without obtaining prior permission from Enac.
In April, a French tourist was arrested in Rome after piloting his camera drone over the Colosseum.
Last year a pair of Israeli tourists were detained for flying their remote-controlled aircraft over the Vatican, while a Korean tourist in Milan found himself in hot water after slamming his drone into the roof of its iconic cathedral.