Some 6 million visitors a year pack the massive tents that dot Munich's sprawling 77-acre (31-hectare) Theresienwiese beer garden during the 16-day festival known across the globe. This year's event began Sept. 19.
The ban - a measure normally reserved for high-ranking state visits - is to remain in place through the end of the festival on Oct. 4.
Islamic terror groups such as al-Qaeda and the Taliban have directed threatening videos and audio messages at Germany in the past two weeks as citizens prepared to vote Sunday in national elections.
The latest video, released by the Taliban late Friday, included pictures of Oktoberfest and threatened attacks on Germany in revenge for its military presence in Afghanistan.
"Given the current security situation, we view a flight ban as necessary," the top security official in the state of Bavaria, Interior Minister Joachim Herrmann, said Saturday.
Oktoberfest has been targeted in the past - Saturday's festival opened with a minute of silence to honor the victims of a bomb attack that killed 13 people and injured 200 others on Sept. 26, 1980.
Every year, visitors down more than 1.6 million gallons (six million liters) of beer and consume 500,000 chickens and 100 oxen at the festival. .