- Jack Dawson: A penniless artist who wins a third-class ticket to America on the Titanic. He falls in love with Rose Dewitt Bukater, a wealthy first-class passenger.
- Rose DeWitt Bukater: A wealthy young woman from Philadelphia who is engaged to Caledon Hockley, a wealthy steel magnate. She meets Jack Dawson and falls in love with him.
- Caledon Hockley: A wealthy steel magnate who is engaged to Rose DeWitt Bukater. He is possessive and controlling, and tries to keep Rose away from Jack Dawson.
- Ruth DeWitt Bukater: Rose's mother, a wealthy socialite who is concerned about her daughter's reputation. She disapproves of Jack Dawson and tries to keep Rose away from him.
- Molly Brown: A wealthy and outspoken first-class passenger who befriends Rose and Jack. She is a survivor of the Titanic disaster and later becomes known as the "Unsinkable Molly Brown."
- Thomas Andrews: The chief designer of the Titanic. He is aware of the ship's flaws but is unable to convince the White Star Line to make changes.
- Edward John Smith: The captain of the Titanic. He is a veteran sailor but is ultimately responsible for the ship's sinking.