Hermann Müller may refer to:

• Hermann Müller (German botanist) (1829–1883), German botanist with whom Darwin corresponded
• Hermann Müller (Swiss botanist) (1850–1927), Swiss botanist
• Hermann Müller (cyclist) (born 1911), German cyclist
• Hermann Müller (politician, born 1876), German Social Democratic politician and twice chancellor of Germany
• Hermann Müller (politician, born 1935), German politician, mayor of Idstein
• Hermann Müller (racewalker) (1885–1947), German race walker
• Hermann Joseph Muller (1890–1967), American geneticist and educator, Nobel laureate in Physiology and Medicine
• Paul Hermann Müller (1899–1965), Swiss chemist, Nobel laureate in Physiology and Medicine
• Hermann Paul Müller (1909–1975), German motorcycle and auto racer driver
• Herman Carl Mueller (1854–1941), German-born American ceramicist