| Cinvention, the 7th World Science Fiction Convention | |
| Venue: | Hotel Metropole |
| Dates: | 3–5 September 1949 |
| Attendance: | ~190 |
The 7th World Science Fiction Convention (Worldcon), also known as Cinvention, was held on 3–5 September 1949 at the Hotel Metropole in Cincinnati, Ohio, United States.
Don Ford carried out the duties of chairman, but was officially Secretary-Treasurer; Charles R. Tanner had the honorary title of chairman.
Attendance was approximately 190.
Noteworthy attendees included Forrest J. Ackerman, Hannes Bok, Lester del Rey. Vince Hamlin. Sam Moskowitz, Rog Phillips, Milton Rothman, "Doc" Smith, and George O. Smith.