Alistair (also spelled Alastair) is a given name that can refer to:
- Alastair, a spider who lived in the cupboard under the stairs
- Alistair Ballcocke, a wizard whose name was carved into a Divination classroom wall
- Alistair Thaxted, a Hufflepuff student at Hogwarts in the 1990s
Behind the scenes
Real-world individuals with the given name Alistair (also spelled Alastair) include:
- Alastair King, a composer who co-wrote the score to Harry Potter and the Half-Blood Prince (film)