- Large boy, thick blond hair on a thick, fat head
- Large, pink face, not much neck
- Small, watery blue eyes
- Resident of Number four, Privet Drive
- Son of Vernon Dursley and Petunia Dursley
- Cousin of Harry Potter
- Spoiled by his parents
- Goes to Smeltings
At the beginning of Harry Potter And The Philosopher's Stone, Dudley is about a year old, living at Number four, Privet Drive with his parents. In HPPS 2, Dudley is celebrating his eleventh birthday by going to the zoo with his friend, Piers Polkiss. Unfortunately, they had to bring Harry along, and there is a mishap in the reptile house when the glass suddenly disappears from the front of a boa constrictor's cage.
Dudley gets his school uniform for Smeltings, his father's alma mater. Shortly thereafter, letters start arriving for Harry. After the first one, addressed to "The Cupboard under the Stairs", Dudley is forced to give up his second bedroom to Harry, despite all his protests. As more and more letters arrive, finally his father takes them all out of the house, and Dudley, missing all of his favourite television programs, begins to think his father is going mad. Mr. Dursley takes them to a shack on an isolated island in the ocean, where no letters should be able to reach them. At midnight, the door bangs open, and Dudley watches terrified as a huge stranger comes in, saying that Harry is a wizard. After arguing with Mr. Dursley, the stranger, Hagrid, casts a spell and gives Dudley a pig's tail, at which point his parents pull him into the other room.