There weren’t many opposition movements in World War II Germany. As the dictator of a totalitarian state, Hitler very effectively used his powers and the secret police force to obliterate any opposition to Nazi rule. The Nazi’s major political rivals in the early days were the Communist party, but they were more or less eliminated as a major opposition movement after the Reichstag Fire. Hitler used this incident to earn emergency powers, which he then used to silence the opposition and solidify his power in Germany.
After the takeover, there were a few small, secretive protest organizations run by university students. The most famous of these was the White Rose, which was a non-violent protest organization, started by students at the University of Munich.
This group distributed anonymous leaflets that called for widespread opposition to Hitler and his party. They borrowed heavily from the Bible, Aristotle and Goethe in their arguments. The leadership core were all philosophy students from the University, and would routinely fling leaflets into the air in order to distribute them without getting caught.
The group was finally undone when a janitor noticed one of the leaders of the group distributing fliers and eventually six of the leaders were rounded up and beheaded. Today they are remembered as heroes of Germany.