An Etymological Dictionary of the German Language/Annotated/Müller

Müller, masculine, ‘miller,’ from Middle High German mülner, mülnœre, neuter (ln is preserved in the surname Müllner, in other cases it is represented by ll), Old High German mûlinâri, masculine, ‘miller.’ A derivative of Mühle (Old High German mulîna), or borrowed directly from Middle Latin molinarius (Italian mulinaro, French meunier), ‘miller.’ See Mühle.