Were any stealth planes used in WWI and WWII?

First World War, no. Radar did not yet exist as weapon that could be used to detect aircraft. read more

Aircraft were very primitive during the war. They fit their function very well, but could not be used for anything too unconventional. Stealth flying was, at the time, definitely unconventional. There were nighttime raids and the like, but aircraft engines in World War 1 were noisy. read more

The first use of stealth aircraft was in the U.S. invasion of Panama, where F-117 Nighthawk stealth attack aircraft were used to drop bombs on enemy airfields and positions while evading enemy radar. read more