Associating something with Hitler does not make that something wrong. Most believers won’t preface their (incorrect) associations of Hitler and evolution with that statement; it’s basic, bald dishonesty.
That said, Hitler was a creationist. In Mein Kampf, he said this:
Walking about in the garden of Nature, most men have the self-conceit to think that they know everything; yet almost all are blind to one of the outstanding principles that Nature employs in her work. This principle may be called the inner isolation which characterizes each and every living species on this earth.
Even a superficial glance is sufficient to show that all the innumerable forms in which the life-urge of Nature manifests itself are subject to a fundamental law–one may call it an iron law of Nature – which compels the various species to keep within the definite limits of their own life-forms when propagating and multiplying their kind.
It is obvious that, yes, Hitler believed that species did not evolve. So what about the Nazi utilization of eugenics? Well, I’m glad you asked such an easy question.
Hitler believed Aryans were inherently superior to everyone else. This is practically identical to the beliefs of most white people (in regard to whites) prior to Darwin. That is, people have long believed their own race to be superior to other races. But Hitler also believed that breeding Aryans with each other would increase Aryan characteristics throughout the population. This wasn’t some idea that depended upon evolutionary theory. People knew for thousands of years that they could produce certain traits within animals by creating breeding programs. Besides that, they obviously recognized that their own children would inherit features from their parents. Hitler extended this common knowledge to Aryans. It had no basis in evolution. Anyone who says otherwise is either woefully ignorant or an unabashed liar.
But how is this different from the position of modern day creationists? Hitler believed traits could be passed on and come to dominate a population. At no point does this have anything to do with speciation from his perspective – nor from the perspective of creationists. This is the so-called “microevolution” that is consistent with the silly creationist view. Hitler did not merely hold it – he embraced it.
Of course, it was not that he was embracing creationism itself. Don’t get me wrong – he did embrace creationism and he was a self-proclaimed creationist many decades before his rise to power – but it was not creationism itself he was embracing. He was using every day intuition about how reproduction works. These ideas stretch back formally at least 2400 years, and probably much further informally in terms of what early humans could observe as obvious. It was day-to-day ideas Hitler was utilizing in his quest for raising the German “superman”. Those ideas really had nothing to do with evolutionary theory, and even if they did, Hitler did not accept that species evolved anyway.