Namesakes
American First Ladies:
1 first lady
Lou Hoover 1929-1933 
Fictional Characters from Song Titles:
2 characters
(character) Mary Lou 1961 Hello Mary Lou
(character) Lou 1986 Captain Lou
Fictional Characters from Television:
3 characters
Lou Grant 1970; 1977 The Mary Tyler Moore Show; Lou Grant
Lou Rodriguez 1984 Miami Vice
Lou Carpenter 1985 Neighbours
Hall-of-Famers:
3 baseball, 2 football, 1 basketball
(baseball) Lou Gehrig 1939
(baseball) Lou Boudreau 1970
(football) Lou Groza 1974
(baseball) Lou Brock 1985
(football) Lou Creekmur 1996
(basketball) Lou Hudson 2022
Most Valuable Players:
2 winners
Lou Gehrig 1927; 1936 baseball
Lou Boudreau 1948 baseball
Notable Actors and Entertainers:
3 actors
Lassie Lou Ahern 1920-2018
Lou Ferrigno 1951-
Lou Diamond Phillips 1962-
Notable Artists:
1 photographer
Annie Leibovitz (a.k.a. Lou) 1949-
Notable Athletes:
3 baseball
(baseball) Lou Gehrig 1903-1941
(baseball) Lou Boudreau 1917-2001
(baseball) Lou Brock 1939-2020
Notable Musicians:
2 musicians
Lou Reed 1942-2013
Lou Bega 1975-
Notable Writers:
1 author
Lou Andreas-Salomé 1861-1937
Olympic Medalists:
1 bronze, 1 bronze/gold, 1 gold
(gold) Lou Jones 1956 4x400 m relay
(bronze/gold) Wendy Boglioli (a.k.a. Lou) 1976 swimming - 100 m butterfly; swimming - 4x100 m freestyle relay
(bronze) Lou Marson 2008 baseball
Rock and Roll Hall-of-Famers:
1 musician
Lou Reed 1996; 2015 The Velvet Underground;