The Crowne Plaza Hotel is hosting Satellite 4 - the 65th annual British Science Fiction Convention.
More than 850 delegates from across the UK, Europe and the US will attend the convention, which runs from today until Monday.
Attendees include science fiction fans, authors, artists and publishers.
Guests of honour include authors Juliet E McKenna and John Meaney, artist Jim Burns and world-renowned British scientist Dame Jocelyn Bell Burnell.
John Wilson of Satellite 4 said: "This is the largest, and longest-running, general science fiction convention held in the UK.
"It's about providing a platform for discussion, networking and knowledge exchange among the world's science fiction community.
"There's far more than the costumed Klingon in the foyer that popular imagination thinks of as the archetypal sci-fi fan.
"The support we have received from Glasgow City Marketing Bureau and the Crowne Plaza Hotel has been fantastic and we're looking forward to welcoming our members from around the world to Glasgow."
The convention has a strong emphasis on sci-fi literature, but also covers film, TV, art, music, space science and technology.
The programme includes a range of panel discussions, specialist talks, workshops, games and quizzes themed around the science fiction and fantasy genres.
Evening activity will include a ceilidh, as well as a play, disco and costume ball. The Scottish Falsetto Sock Puppet Theatre will also perform.
There will be swap meet, where delegates can trade and buy books, T-shirts, jewellery, ceramics and other memorabilia.
An art exhibition will feature works by professional and fan artists, some of which will be auctioned on Sunday.
Satellite 4 is organised and run entirely by volunteers on a not-for-profit basis.
A donation will be made from surplus funds to Macmillan Cancer Support.
For more information, visit www.satellite4.org.uk