Karl Müller may refer to:
Karl Müller (astronomer) (1866–1942), Austrian astronomer Karl Müller (botanist) (1817–1870), German botanist and mycologist Karl Müller (botanist, born 1893) (1893–1955), German botanist Karl Müller (bryologist) (1818–1899), German bryologist Karl Müller (bryologist, born 1881) (1881–1955), German bryologist Karl Müller (inventor) (born 1952), Swiss inventor and engineer Karl Müller (rower) (1912–?), Swiss Olympic rower Karl H. Müller (born 1953), Austrian social scientist Karl Otfried Müller (1797–1840), German classical scholar and admirer of Dorians and Spartans Karl Wilhelm Ludwig Müller (1813–1894), German classical scholar and editor of Fragmenta Historicorum Graecorum K. Alex Müller (Karl Alexander Müller, 1927–2023), Swiss physicist, 1987 Nobel Prize Karl Müller (politician, born 1884) (1884–1964), German politician
See also Karl von Müller (1873–1923), German naval captain Karl Mueller (1963–2005), U.S. rock musician Carl Muller (1935–2019), Sri Lankan writer Carl A. Muller (1913–1991), Canadian politician Carl Otto Müller (1901–1970), German painter