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 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.
- Season 5 - Gordon and the Gremlin (not named)
- Season 6 - It's Only Snow (cameo) and Thomas the Jet Engine (cameo)
- Her title, Dowager, means someone who is a widow with a noble title so this means that her husband is deceased.