Namesakes
Benny Nielsen
(a.k.a. Leo) (m) 1966- 
Olympic Medalists 1988 swimming - 200 m butterfly (silver)
Branscombe Richmond
(a.k.a. Leo) (m) 1955-
Notable Actors and Entertainers (actor)
Flavius Valerius Leo
(a.k.a. Leo) (m) 401-474
Roman and Byzantine Emperors 457-474
Flavius Leo Junior
(a.k.a. Leo) (m) 467-474
Roman and Byzantine Emperors 474
Gabby Hartnett
(a.k.a. Leo) (m) 1900-1972
Hall-of-Famers 1955 (baseball)
Most Valuable Players 1935 baseball
James Dillion
(a.k.a. Leo) (m) 1929-2010
Olympic Medalists 1952 discus throw (bronze)
Johnny Hallyday
(a.k.a. Léo) (m) 1943-2017
Notable Musicians
Joseph L. Mankiewicz
(a.k.a. Leo) (m) 1909-1993
Notable Filmmakers
Oscar Award Winners 1950; 1951 A Letter to Three Wives; All About Eve (director)
Lee J. Cobb
(a.k.a. Leo) (m) 1911-1976
Notable Actors and Entertainers (actor)
Leo
(m)
Characters in Greek Mythology
Leo
(m) ?-260
Saints
Leo I the Great
(m) c. 400-461
Bishops of Rome and the Popes 440-461
Saints (Leo the Great)
Leo
(m) ?-541
Saints
Leo
(m) ?-550
Saints
Leo II
(m) 611-683
Bishops of Rome and the Popes 682-683
Saints
Leo
(m) 685-741
Roman and Byzantine Emperors 717-741
Leo
(m) ?-706
Roman and Byzantine Emperors 695-698
Leo III
(m) 750-816
Bishops of Rome and the Popes 795-816
Saints
Leo
(m) 750-780
Roman and Byzantine Emperors 775-780
Leo
(m) 775-820
Roman and Byzantine Emperors 813-820
Leo
(m) ?-787
Saints
Leo IV
(m) 790-855
Bishops of Rome and the Popes 847-855
Saints
Leo of Carentan
(m) 856-890
Saints
Leo
(m) 866-912
Roman and Byzantine Emperors 886-912
Leo VI
(m) 880-928
Bishops of Rome and the Popes 928
Leo Luke
(m) ?-900
Saints
Leo
(m) ?-900
Saints
Leo V
(m) ?-904
Bishops of Rome and the Popes 903
Leo VII
(m) ?-939
Bishops of Rome and the Popes 936-939
Leo VIII
(m) ?-965
Bishops of Rome and the Popes 964-965
Leo of Nonantula
(m) ?-1000
Saints
Leo IX
(m) 1002-1054
Bishops of Rome and the Popes 1049-1054
Saints
Leo of Lucca
(m) ?-1079
Saints
Leo of Saint-Bertin
(m) ?-1163
Saints
Leo X
(m) 1475-1521
Bishops of Rome and the Popes 1513-1521
Leo XI
(m) 1535-1605
Bishops of Rome and the Popes 1605
Leo XII
(m) 1760-1829
Bishops of Rome and the Popes 1823-1829
Leo XIII
(m) 1810-1903
Bishops of Rome and the Popes 1878-1903
Leo Boivin
(m) 1931-2021
Hall-of-Famers 1986 (ice hockey)
Notable Athletes (ice hockey)
Leo Canjels
(m) 1933-2010
Notable Athletes (soccer)
Leo von Caprivi
(m) 1831-1899
German Chancellors and Presidents 1890-1894 (chancellor)
Leo Carrillo
(m) 1880-1961
Notable Actors and Entertainers (actor)
Leo G. Carroll
(m) 1886-1972
Notable Actors and Entertainers (actor)
Leo Chingkwake
(m)
Fictional Characters from Television 1998 That '70s Show
Leo Dalton
(m)
Fictional Characters from Television 1996 Silent Witness
Léo Delibes
(m) 1836-1891
Notable Musicians
Leo Durocher
(m) 1905-1991
Hall-of-Famers 1994 (baseball)
Leo Falcam
(m) 1935-2018
Other Leaders 1999-2003 Federated States of Micronesia (president)
Leo Fender
(m) 1909-1991
Notable Businesspeople
Notable Scientists and Inventors
Leo Fisher
(m)
Fictional Characters from Television 1999 Once and Again
Leo Genn
(m) 1905-1978
Notable Actors and Entertainers (actor)
Leo Goodwin
(m) 1883-1957
Olympic Medalists 1904; 1908 diving - plunge for distance; swimming - 4x50 yard freestyle relay; water polo; swimming - 4x200 m freestyle relay (bronze/gold)
Leo Howard
(m) 1997-
Notable Actors and Entertainers (actor)
Leo Karasuma
(m) ?-1597
Saints
Leo Komarov
(m) 1987-
Olympic Medalists 2014 ice hockey (bronze)
Leo Kombiogi
(m) ?-1628
Saints
Leo Larrivee
(m) 1903-1928
Olympic Medalists 1924 3000 m team (bronze)
Leo Ignatius Mangin
(m) ?-1900
Saints
Leo Markus
(m)
Fictional Characters from Television 1998 Will & Grace
Leo Mason
(m)
Fictional Characters from Television 2012 Major Crimes
Leo McCarey
(m) 1898-1969
Notable Filmmakers
Oscar Award Winners 1938; 1945 The Awful Truth; Going My Way (director)
Leo McKern
(m) 1920-2002
Notable Actors and Entertainers (actor)
Leo Nakanishi
(m) ?-1619
Saints
Leo Nomellini
(m) 1924-2000
Hall-of-Famers 1969 (football)
Leo Peelen
(m) 1968-2017
Olympic Medalists 1988 cycling - track (silver)
Leo Satsuma
(m) ?-1622
Saints
Leo Sayer
(m) 1948-
Notable Musicians
Leo Sexton
(m) 1909-1968
Olympic Medalists 1932 shot put (gold)
Leo Suchiemon
(m) ?-1622
Saints
Leo Tanaka
(m) ?-1617
Saints
Leo Tindemans
(m) 1922-2014
Belgian Prime Ministers 1974-1978
Leo Tolstoy
(m) 1828-1910
Notable Writers
Leo Varadkar
(m) 1979-
Irish Presidents and Prime Ministers 2017-2020; 2022-2024 (prime minister)
Leo Visser
(m) 1966-
Olympic Medalists 1988; 1992 speed skating (silver/bronze)
Leo Wyatt
(m)
Fictional Characters from Television 1998 Charmed
Leonardo Gutiérrez
(a.k.a. Leo) (m) 1978-
Olympic Medalists 2004; 2008 basketball (gold/bronze)
Leonel Manzano
(a.k.a. Leo) (m) 1984-
Olympic Medalists 2012 1500 m (silver)
Leonhard Pohl
(a.k.a. Leo) (m) 1929-2014
Olympic Medalists 1956 4x100 m relay (bronze)
Norman "Fatboy Slim" Cook
(a.k.a. Leo) (m) 1963-
Notable Musicians
Reona Esaki
(a.k.a. Leo) (m) 1925-
Nobel Prize Winners 1973 (physics)
Notable Scientists and Inventors
Taye Diggs
(a.k.a. Leo) (m) 1971-
Notable Actors and Entertainers (actor)
Veikko Karvonen
(a.k.a. Leo) (m) 1926-2007
Olympic Medalists 1956 marathon (bronze)