Thiemann is a surname. Notable people with the surname include:
Carl Thiemann (1881–1966), Bohemian printmaker Elsa Thiemann (1910–1981), German photographer Hugo Thiemann (1917–2012), Swiss electronics engineer Johannes Thiemann (born 1994), German basketball player Ronald Frank Thiemann (1946–2012), American academic
See also Thiemann Scott Offutt (1872–1943), justice of the Maryland Court of Appeals