The Battle of Fornebu was an engagement that occurred on 9 April 1940 during Operation Weserübung when the Germans launched an assault on Oslo, the capital of Norway.

The Norwegians had dispatched fighters to intercept them, but the Gloster Gladiators were not able to catch up with the newer and faster German planes.

One Norwegian fighter was shot down by the Germans, but all Gloster Gladiators eventually ran out of gas and landed in various places around Oslo.

[2] Fornebu Airport was originally supposed to be secured by paratroops an hour before the first troops were flown in, but the initial force became lost in the fog and did not arrive.

The ground personnel of the Norwegian Army Air Service soon ran out of ammunition for their anti-aircraft machine guns as well; in the general confusion and focus on readying the fighters for action, no one had the presence of mind or the time to issue small-arms ammunition for the personal weapons of the ground personnel.