Kellner is a surname. Notable people with the surname include:
Alex Kellner (1924–1996), baseball pitcher
Alexander Kellner (born 1961), Brazilian paleontologist
Carl Kellner (optician) (1829–1855), German optician
Carl Kellner (mystic) (1851–1905), Austrian mystic, founder of Ordo Templi Orientis
Catherine Kellner (born 1970), American actress
Dan Kellner (born 1976), American fencer and graphic designer
Donald Ferdinand Kellner (1879-1935), Canadian politician
Douglas Kellner (born 1943), American philosopher
Esther Kellner (1908 - 1998), American author
Friedrich Kellner (1885–1970), Justice Inspector and Nazi opponent
Gyula Kellner (1871-1940), Hungarian athlete
Jamie Kellner, American television executive
Ján Kellner, S.J. (1912-1941), Slovak Catholic priest and missionary to USSR
Johann Christoph Kellner (1736 – 1803), German composer, son of Johann Peter Kellner
Johann Peter Kellner (1705 – 1772), German composer, father of Johann Christoph Kellner
Leon Kellner (1859 – 1928), Grammarian, Shakespearean, and Zionist
Lorenz Kellner (1811-1892), German educator
Larry Kellner (born 1959), American businessman
Micah Kellner (born 1978), American politician
Oscar Kellner (1851–1911), German agronomist
Paul Kellner (1890 – 1972), German swimmer
Peter Kellner (born 1946), British journalist
Petr Kellner (born 1964), Czech businessman and wealthiest person in the Czech Republic
Rosa Kellner (1910 – 1984), German athlete
Uwe Kellner, German rower
Walt Kellner (1929 – 2006), American Major League Baseball player
William Kellner (1900 - 1996), British-Austrian art director
