I have visited a few museums in Germany, and can't recall ever seeing a statue of Hitler. I've also never seen any in old photographs or documentary footage. my understanding is that the Nazi state was essentially one big cult of personality around the Fuhrer. We know that Hitler widely appropriated symbols and propaganda techniques from both the Catholic Church and the Communist party, both of which seem obsessed with statuary. So why wasn't every street corner festooned with statues of the Fuhrer, the same way busts of Lenin are found everywhere in the former eastern bloc?
That probably has something to do with the Allies removing and/or destroying Nazi insignia on public buildings to prevent those sites from becoming "shrines" to Nazism and Hitler.
A good case in point are the Nuremberg rally grounds, which were featured in Leni Riefenstahl's Triumph of the Will. If one visits them now, the places where the swastikas and eagles and other Nazi symbols were mounted are easily visible, but the symbols themselves are long gone.
I'm not sure just how successful a policy like that can be, since people who still buy into that (and tourists who are interested in that era of German history) can still gather at those locations whether the symbols are there or not.
Another part of it would be the fact that it is illegal in Germany to display Nazi flags and/or other symbols, or to publicly endorse Hitler and the Nazi party.
We have two answers assuming that statues of Hitler were destroyed after WWII, but, (Follow on question):
Do we know if any statues of Hitler were ever made?