The term Wunderwaffe (pronounced "voo-nahr-vah-fuh") is a German word that means "wonder-weapon" or "miracle weapon." During World War II, Nazi Germany's propaganda ministry used this term to describe some advanced weapons they claimed could change the course of the war. However, most of these weapons were never fully developed or used in battle. A few, such as the V-weapons, were created earlier and used more often, especially against cities like London and Antwerp. These weapons came from the same group of ideas for new military technology. Today, the word Wunderwaffe in German usually refers to a solution that seems to fix all problems related to a specific issue, but it is often used in a way that highlights how such solutions are not realistic.

As Germany's situation in the war grew worse in 1942, the government began promoting claims about new, powerful weapons that could help turn the war in their favor. In reality, developing these advanced weapons required long periods of planning and testing. There was no realistic chance that Germany could use them before the war ended. When some designs, like the Panther tank and Type XXI submarine, were made quickly without proper testing, their performance was disappointing. Historian Michael J. Neufeld has written that the result of these efforts was that Germany wasted a lot of money, technical knowledge, and the lives of forced and slave laborers to create weapons that provided little or no real military benefit.