Morgan Freeman was filming the crisis room scenes in Louisiana at the height of his Internet death hoax. He often began each day of filming by serenading the extras with old jazz songs and endeared himself to the unsuspecting crew with pranks.
While the film's choice of North Korea as the driver of the plot and source of the villains was widely viewed as prescient when a number of real-world tensions between the Democraric People's Republic of Korea and the United States of America emerged in 2013, the script and production made that choice years earlier. Director Antoine Fuqua said in an interview that he did not want the film's villains to be from the Middle East, a choice he felt had been covered to the point of saturation in other films, and that North Korea was interesting to him because it was a country that was completely closed off to the outside world and therefore projected a sense of no one really knowing what it wanted or was capable of doing.
It was so hot in Louisiana during the filming of the White House tourist scenes that the Humane Society representative insisted that the German Shepherds being used as K-9 watch dogs be kept in an air-conditioned van between shoots.
Gerard Butler was once in consideration to star as CIA operative Mitch Rapp in a proposed film adaptation of Vince Flynn's novels. One of those has an extremely similar plot to Olympus Has Fallen: terrorists seize control of the White House, and Rapp must get to the President in his bunker before the terrorists do.
Melissa Leo did step-ups on an apple box in-between takes of her more physically-demanding scenes to keep her heart-rate up. Leo also wore a brown wig, because she needed to keep her hair long while shooting Treme (2010), simultaneously.
The intruding aircraft is a modified version of the Lockheed AC-130, itself a modified version of the C-130 Hercules. In the movie the plane features two GE M134 miniguns on each side of the plane; the real aircraft only has air-to-ground armament on the port (left) side to provide close air support to ground troops, among other high risk tasks.
After the attack on the White House and kidnapping of the President and Vice President, Speaker Allan Trumbull (Morgan Freeman) becomes Acting President of the United States. Freeman previously played the President of United States in Deep Impact (1998).