| Discon I, the 21st World Science Fiction Convention | |
| Dates: | 31 August – 2 September 1963 |
| Filing: | non-profit |
| Attendance: | ~600 |
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.
Attendance was approximately 600.
Following the convention, published The Proceedings: Discon, edited by Richard Eney. The book includes transcripts of lectures and panels given during the course of the convention and includes numerous photographs as well.