1st World Science Fiction Convention

NyCon I, the 1st World Science Fiction Convention
GenreScience fiction
Dates2–4 July 1939
VenueCaravan Hall
Location(s)New York City
CountryUnited States
Attendance~200

The 1st World Science Fiction Convention (Worldcon) was held on 2–4 July 1939 in the Caravan Hall in New York City, New York, in conjunction with the New York World's Fair, which was themed as "The World of Tomorrow". It was later retroactively named "NyCon I" by Forrest J Ackerman.

The convention was chaired by Sam Moskowitz. Along with Moskowitz, other organizers were James V. Taurasi, Sr. and Will Sykora.