The claim that Stephen Miller is the grandson of Heinrich Müller, the Bavarian head of the Gestapo, is false because there is no credible evidence or reliable sources linking Stephen Miller's family to Heinrich Müller, whose fate remains unknown and who has no documented descendants.
Stephen Miller is the Grandson of German Heinrich Müller who was the Bavarian head of the Gestapo.

Heinrich Müller
Source: holocausthistoricalsociety.org.uk
Key Evidence
Heinrich Müller's biography and historical records do not document any known descendants.
holocausthistoricalsociety.org.ukholocausthistoricalsociety.org.ukHeinrich Müller
britannica.combritannica.comHeinrich Müller+1 more
His disappearance after WWII and lack of confirmed death contribute to the absence of family information.
reddit.comreddit.comTIL The head of the Gestapo during WW2, Heinrich Muller, was never found....
reddit.comreddit.comr/ww2 on Reddit: What happened to Heinrich Müller the gestapo chief?
No reputable sources connect Stephen Miller to Heinrich Müller in any genealogical or biographical context.
What the Evidence Shows
Heinrich Müller was indeed the head of the Gestapo during Nazi Germany, as confirmed by multiple historical sources.holocausthistoricalsociety.org.ukholocausthistoricalsociety.org.ukHeinrich Müller
britannica.combritannica.comHeinrich Müller+1 more He was born in Munich, Bavaria, and was a high-ranking SS officer and police official.
However, his fate after World War II remains a mystery, with no confirmed death or known family lineage publicly documented.reddit.comreddit.comTIL The head of the Gestapo during WW2, Heinrich Muller, was never found....
warhistoryonline.comwarhistoryonline.comWhat Happened To Gestapo Chief And Nazi War Criminal Heinrich Müller+1 more There is no credible historical or genealogical evidence connecting Stephen Miller, a contemporary American political figure, to Heinrich Müller. The claim appears to be a misinformation or conspiracy theory without basis in verified records or reputable biographies.
None of the authoritative sources on Heinrich Müller mention any descendants or familial ties to Stephen Miller or his family. Given the absence of any reliable documentation or credible reporting supporting this familial link, the claim is unsubstantiated and false.