World Science Fiction Convention (Worldcon)
Worldcon is the annual convention of WSFS. It was first held in 1939 and, after a short break for WWII, has been held continuously since 1946. The sites of future Worldcons are decided by WSFS members via a bidding process. For more information about Worldcon, including a list of currently seated conventions and information on how to bid to hold the event in your city, see the convention’s website.

North American Science Fiction Convention (NASFiC)
The NASFiC is held only in years when the Worldcon is held outside of North America. Like Worldcon, the site is chosen via a bidding process. For more information about NASFiC see the convention’s website.