FlorenceJean "Flo" Castleberry, character on TV's "Alice" and "Flo"
Flo, Progressive Insurance advertising character
Flo, main character in the Diner Dash game series
Flo, character in Pixar's "Cars" films
Aunt Flo, plump landlady of the Potwell Inn in "The History of Mr. Polly" (1910) by H. G. Wells