The tourists — a father and his son — were held by police after they launched a drone near one of the Kremlin's iconic towers.
Police told AFP that the pair were released after being handed an unspecified fine.
“You don't go to prison for things like that,” police spokeswoman Anastasia Samorodova told AFP.
Violating airspace regulations in Russia can entail a fine of up to 5,000 rubles ($76).
Sightings of drones and other flying devices are becoming increasingly common at tourist attractions and sporting events around the globe.
A drone crashed at the US Open earlier this month, causing a match to be interrupted.
There was a similar incident at Wimbledon in July as some of the world's top players warmed up for the Grand Slam in south-west London.
In April, an American anti-corruption activist was arrested after having landed a mini helicopter on the lawn of the US Capitol and piloting it through Washington's no-fly zone, alarming national security.
Drones were also seen over several high-profile areas of Paris earlier this year when the city was on high alert after three gunmen killed 17 in January.