Louie is a surname. It is also a Taishanese variation of Lei (surname). People surnamed Louie include:
Alexina Louie (born 1949), Canadian composer
Brandt C. Louie (born 1943), Canadian accountant and businessman
Clarence Louie (born 1960), Canadian First Nations leader and businessman
David M. Louie (born 1951), American attorney, former Attorney General of Hawaii
"Lakewood" Louie, American poker player best known for his success at the World Series of Poker in the late 1970s and early 1980s
Steven Gwon Sheng Louie (born 1949), Chinese physicist