| Seacon, the 19th World Science Fiction Convention | |
| Venue: | Hyatt House Hotel |
| Dates: | 2–4 September 1961 |
| Filing: | Non-profit |
| Attendance: | 270 to 300 |
The 19th World Science Fiction Convention (Worldcon), also known as Seacon, was held on 2–4 September 1961 at the Hyatt House Hotel in Seattle, Washington, United States.
The convention chair was Wally Weber.
Attendance was approximately 270 to 300.
Heinlein gave a speech titled "The Future Revisited". He was previously the guest of honor at the 3rd Worldcon, and would again be the guest of honor at the 34th Worldcon.