21st World Science Fiction Convention
| Discon I, the 21st World Science Fiction Convention | |
|---|---|
| Genre | Science fiction | 
| Dates | 31 August – 2 September 1963 | 
| Venue | Statler-Hilton Hotel | 
| Location(s) | Washington, D.C. | 
| Country | United States | 
| Attendance | ~600 | 
| Filing status | non-profit | 
The 21st World Science Fiction Convention (Worldcon), also known as Discon I, was held on 31 August through 2 September 1963 at the Statler-Hilton Hotel in Washington, D.C., United States.
The chairman was George Scithers.