- "This lady is my mother. And she agrees with me; you are indeed really useful engines, and my mother, of course, is always right!"
- ―Sir Topham Hatt, Gordon and the Gremlin, fifth season
- "Well, Thomas. I must admit that, for once, my mother was right!"
- ―Sir Topham Hatt, Buckled Tracks and Bumpy Trucks, twentieth season
Dowager Hatt is Sir Topham Hatt's elderly mother.
In her first visit to Sodor, Thomas was charged with bringing her to Kirk Ronan, where Gordon would then take her on a VIP tour. She later visited Sodor several times, including once to celebrate her birthday.
During her youth, she used to be a very good opera singer, though her son does not like hearing it. She owns a Dalmatian, which she renamed "Gremlin" after her adventure with Gordon's "gremlins".
She later attended Sir Robert Norramby's Christmas Luncheon and became cross when Sir Topham Hatt failed to show up for a lunch date, and went out to find him on board Thomas.
When her son caught a cold, Dowager Hatt forced him to stay home and ran the railway in his place. Confusion and delay quickly ensured, however, when she forced the engines to perform trivial tasks for her, such as sending Thomas to collect a new hat for her from the docks, and gave engines tasks unsuited to their abilities, such as having Percy pull the Express. When Emily pointed this out to her, she was saddened that she had failed her son. Fortunately, by working together, Dowager Hatt and Emily were able to get the railway back on track by the time Sir Topham returned that evening.
She is a bit of a thrill-seeker, and hates going slow and resting. She hates nonsense, and is shown not to believe in mythical creatures such as the Abominable Snowman. She loves her son, Sir Topham, and opera singing.
Dowager Hatt usually wears a green dress and a green hat, with a gold band and a red flower on it. During the winter she wears a purple dress and purple hat with a lighter purple flower on it.
- Keith Wickham (UK/US; thirteenth season onwards)
- Fu Suzuki (Japan; fifth season only)
- Keiko Nemoto (Japan; ninth season onwards)
- Margrit Strassburger (Germany; thirteenth season onwards)
- Ewa Serwa (Poland; thirteenth - sixteenth seasons)
- Anna Apostolakis (Poland; eighteenth season onwards)
- Lena Meieran (Norway; thirteenth - sixteenth seasons, excluding Day of the Diesels)
- Marianne Westby (Norway; Day of the Diesels only)
- Talya Barkay (Israel; fifteenth season onwards)
- Blanche Ravalec (France and French speaking Canada; ninth season onwards)
- Loretta Santini (Latin America; thirteenth season onwards)
- Mercedes Espinosa (Spain)
- Susa Saukko (Finland; thirteenth season onwards)
- Her title, Dowager, means someone who is a widow with a noble title so this means that her husband is deceased.
- Dowager Hatt's appearance has changed over the course of the television series.
- Season 12:
- Her eye color changed from brown to blue.
- She appears to have lost a significant amount of weight.
- Season 18:
- The wrinkles on her forehead become more prominent.
- Her skin becomes paler.
- Season 12: