Kate Gandor (ケイト・ガンドール, Keito Gandōru) is the charitable and compassionate wife of mobster Keith Gandor. She is a pianist who used to play for silent movies, and has a minor role in the events of 1932.
Despite being a wife of a renowned mob boss, Kate is actually very kind and welcoming to strangers due to the current situation of the Depression. She is known to be a very hospitable woman and allows guests to join her for dinner, and though her husband never makes it home due to the nature of his work, she loves him none the less and is very supportive of him. Of all people in the Baccano! universe, her mysterious and inviting demeanour is the only one capable of making the silent Keith Gandor able to speak more than a few words. He speaks so rarely that anything he says is information highly sought by the Daily Days and other organizations.
She opens the fourth volume with a small introduction as her music silently plays over the streets of New York.
Kate appears late in the novels when during a visit the office of the Gandor Brothers she runs into Roy Maddock and Eve Genoard. Mistaking them for associates, she invites the two to her home and treats them to dinner. There she explains her motivations in staying by her husband's side: she was once an organist for silent films. During the later 1920s, where silent movies were made obsolete by "talkies," she was left jobless. Keith Gandor eventually sought her out to play more pieces of music for him, and eventually they married. After dinner, she plays a beautiful piece of music improvised to entertain the duo while they wait for Keith, so they can meet with the younger brother Luck Gandor. Eve and Kate get along well, however Roy remains distant due to his plans in using Eve for a hostage and his guilt. The three part ways with Eve promising to make time to visit them once the crisis is over.
She closes the book with a beautiful note that resonates through the streets of the city in the wake of the Gandor-Runoratta turf war, signifying well wishes to the main protagonists in the storyline.