Walter Müller or Mueller may refer to:

• Walter Mueller (1894–1971), American baseball player
• Walter H. Mueller (?–2011), American politician
• Walter Müller (actor) (1911–1969), Austrian film actor
• Walter Müller (biathlete) (1940–1966), Austrian Olympic biathlete
• Walter Müller (Panzerjäger) (1914–2003), German army officer
• Walter Müller (footballer, born 1938) (born 1938), Swiss footballer
• Walter Müller (footballer, born 1970) (born 1970), Swiss footballer
• Walter Müller (footballer, born 1920) (1920–2010), Swiss footballer
• Walter Müller (footballer, born 1910) (1910–?), Swiss footballer
• Walter Müller (German gymnast) (1930–2021), German Olympic gymnast
• Walter Müller (Swiss gymnast) (born 1940), Swiss Olympic gymnast
• Walter Müller (handballer) (born 1957), Swiss handballer
• Walter Andreas Müller (born 1945), Swiss stage and film actor
• Walter W. Müller (born 1933), German specialist in ancient South Arabia and Semitic epigraphy
• Walter Müller (writer), Austrian writer, winner of an award at the 1979 Festival of German-Language Literature