Daisy Miller, the charming and unconforming American tourist whose inattention to decorum (she walks unchaperoned with an Italian suitor in the daytime) results in her ostracism by the Europeanized Americans in Rome. In defiance, she visits the Colosseum at night with the same young man and later dies of a fever contracted there.
Frederick Winterbourne, an American expatriate from whose point of view the story is told. At first puzzled by Daisy, he soon becomes convinced that she is immoral. After her death, however, he realizes that he loved her, and that her manners indicated only a native American freedom.
Giovanelli, the young Italian whose companionship causes the scandal involving Daisy. An adventurer interested primarily in Daisy’s money, he admits to Winterbourne after her death that she never would have consented to marry him.
Mrs. Walker, an American expatriate. Because Daisy rejects Mrs. Walker’s efforts to preserve her from scandal, Mrs. Walker cuts her at a party, thus beginning Daisy’s complete ostracism.
Randolph Miller, Daisy’s young and spoiled brother. His impudence also shocks the American expatriates.
Mrs. Costello, Winterbourne’s aunt. She refuses to meet Daisy because she is convinced that the Millers are common.
Eugenio, the Millers’ courier and servant. That the Millers treat him almost as a member of the family also causes talk among the American expatriates.