Bridget Amanda Hatt (born 1943) is Sir Topham and Lady Hatt's granddaughter, Stephen's younger sister, Dowager Hatt's great-granddaughter and Sir Lowham Hatt's great-niece. She is two years younger than her brother, Stephen.
Bridget, like her brother, has never been shown to age, and has always stayed the same age ever since the first season. She and her brother helped Toby to find an abandoned castle. When it was her birthday, James was sent to collect her and take her to the town hall, and she took a liking to the pink undercoat he was painted in. She later caught chickenpox along with Stephen, indirectly convincing Henry that engines could also catch chickenpox.
- Teresa Gallagher (UK; thirteenth season onwards - US; nineteenth season onwards)
- Jules de Jongh (US; thirteenth and fourteenth season only)
- In the magazine story, The Hallowe'en Special, it is said that Stephen and Bridget live on the Mainland and come to stay with Lady and Sir Topham Hatt once in a while.
- In the television series, Bridget's hair colour is brown. In Toby the Tram Engine and the magazine stories, it is blonde.
- In Thomas Comes to Breakfast, Bridget appeared as the Stationmaster's daughter.
- A large scale head of Bridget Hatt is preserved by The Coffey Man Preservation from The Prop Gallery.
- Departing Now