Namesakes
Otto von Bismarck
(m) 1815-1898 
German Chancellors and Presidents 1871-1890 (chancellor)
Otto I the Great
(m) 912-973
German Kings and Holy Roman Emperors 936-973
Otto Stern
(m) 1888-1969
Nobel Prize Winners 1943 (physics)
Notable Scientists and Inventors
Otto Hahn
(m) 1879-1968
Nobel Prize Winners 1944 (chemistry)
Notable Scientists and Inventors
Otto Wallach
(m) 1847-1931
Nobel Prize Winners 1910 (chemistry)
Notable Scientists and Inventors
Otto II the Red
(m) 955-983
German Kings and Holy Roman Emperors 961-983
Otto Diels
(m) 1876-1954
Nobel Prize Winners 1950 (chemistry)
Notable Scientists and Inventors
Adolf Eichmann
(a.k.a. Otto) (m) 1906-1962
Notable Evildoers
Karel III
(middle name Otto) (m) 1887-1922
Bohemian Kings 1916-1918
Austrian Dukes and Emperors (Karl I) 1916-1918
Saints (Karl of Austria)
Hungarian Kings and Queens (Károly IV) 1916-1918
Otto III
(m) 980-1002
German Kings and Holy Roman Emperors 983-1002
Otto von Guericke
(m) 1602-1686
Notable Scientists and Inventors
Adolf Windaus
(middle name Otto) (m) 1876-1959
Nobel Prize Winners 1928 (chemistry)
Notable Scientists and Inventors
Karl Lagerfeld
(middle name Otto) (m) 1933-2019
Notable Artists
Otto IV
(m) 1175-1218
German Kings and Holy Roman Emperors 1198-1215
Otto Heinrich Warburg
(m) 1883-1970
Nobel Prize Winners 1931 (medicine)
Otto of Greece
(m) 1815-1867
Other Royalty 1832-1862 Greece (king)
Heinrich Otto Wieland
(m) 1877-1957
Nobel Prize Winners 1927 (chemistry)
Otto Fritz Meyerhof
(m) 1884-1951
Nobel Prize Winners 1922 (medicine)
Ernst Otto Fischer
(m) 1918-2007
Nobel Prize Winners 1973 (chemistry)
Otto Loewi
(m) 1873-1961
Nobel Prize Winners 1936 (medicine)
Otto Wagner
(m) 1841-1918
Notable Artists
Otto Sander
(m) 1941-2013
Notable Actors and Entertainers (actor)
Otto Dix
(m) 1891-1969
Notable Artists
Otto Preminger
(m) 1905-1986
Notable Filmmakers
Ottó III of Bavaria
(m) 1261-1312
Hungarian Kings and Queens 1305-1308
Otto Rehhagel
(m) 1938-
Notable Athletes (soccer)
Claus of the Netherlands
(middle name Otto) (m) 1926-2002
Other Royalty 1980-2002 Netherlands (prince consort)
Otto Franz Joseph of Austria
(m) 1865-1906
Other Royalty 1865-1906 Austria-Hungary (archduke)
Otto the Merry
(m) 1301-1339
Austrian Dukes and Emperors 1330-1339
Otto of Bamberg
(m) 1060-1139
Saints
Jens Otto Krag
(m) 1914-1978
Danish Prime Ministers 1962-1968; 1971-1972
Otto Mueller
(m) 1874-1930
Notable Artists
Eric Lemming
(middle name Otto) (m) 1880-1930
Olympic Medalists 1908; 1912 javelin throw - freestyle; javelin throw (gold)
Otto Strandman
(m) 1875-1941
Estonian Presidents and Prime Ministers 1919; 1929-1931 (prime minister/state elder)
Hans Woellke
(middle name Otto) (m) 1911-1943
Olympic Medalists 1936 shot put (gold)
Jonathan Motzfeldt
(middle name Otto) (m) 1938-2010
Other Leaders 1979-1991; 1997-2002 Greenland (prime minister)
Otto Friedrich Müller
(m) 1730-1784
Notable Scientists and Inventors
Otto Herschmann
(m) 1877-1942
Olympic Medalists 1896 swimming - 100 m freestyle (silver)
Otto Ender
(m) 1875-1960
Austrian Chancellors and Presidents 1930-1931 (chancellor)
Otto Tief
(m) 1889-1976
Estonian Presidents and Prime Ministers 1944 (prime minister)
Dénes Berinkey
(middle name Ottó) (m) 1871-1944
Hungarian Presidents and Prime Ministers 1919 (prime minister)
Otto Blehr
(m) 1847-1927
Norwegian Prime Ministers 1921-1923
Tage Reedtz-Thott
(middle name Otto) (m) 1839-1923
Danish Prime Ministers 1894-1897
Otto Stich
(m) 1927-2012
Swiss Presidents 1988; 1994
Georg von Rosen
(middle name Otto) (m) 1843-1923
Notable Artists
Otto B. Halvorsen
(m) 1872-1923
Norwegian Prime Ministers 1920-1921; 1923
Otto Scheff
(m) 1889-1956
Olympic Medalists 1908 swimming - 400 m freestyle (bronze)
Otto Wahle
(m) 1879-1963
Olympic Medalists 1900; 1904 swimming - 1500 m freestyle; swimming - 200 m obstacle; swimming - 400 m freestyle (silver/bronze)
Otto Fahr
(m) 1892-1969
Olympic Medalists 1912 swimming - 100 m backstroke (silver)
Otto Liebe
(m) 1860-1929
Danish Prime Ministers 1920
Ottó Boros
(m) 1929-1988
Olympic Medalists 1956; 1960; 1964 water polo (gold/bronze)
Otto Nilsson
(m) 1879-1960
Olympic Medalists 1908 javelin throw (bronze)
Herbert Schade
(middle name Otto) (m) 1922-1994
Olympic Medalists 1952 5000 m (bronze)
Otto Trieloff
(m) 1885-1967
Olympic Medalists 1908 medley relay (silver)
Otto Cordes
(m) 1905-1970
Olympic Medalists 1928; 1932 water polo (gold/silver)
Otto Neumann
(m) 1902-1990
Olympic Medalists 1928 4x400 m relay (silver)
Otto Graham
(m) 1921-2003
Hall-of-Famers 1965 (football)
Notable Athletes (football)
Ruud van Feggelen
(middle name Otto) (m) 1924-2002
Olympic Medalists 1948 water polo (bronze)
Otto
(m)
Hurricanes and Tropical Storms 2016 (hurricane)
Otto Neururer
(m) 1882-1940
Saints
Otto Hesselbom
(m) 1848-1913
Notable Artists
Otto Flick
(m)
Fictional Characters from Television 1982 'Allo 'Allo!
Otto
(m)
Hurricanes and Tropical Storms 2004 (storm)
Otto
(m)
Hurricanes and Tropical Storms 2010 (hurricane)
Otto Boffin
(m)
Tolkien's Characters