Dates: Thursday 24th to Monday 27th April 1998
International Guest of Honour: Lois McMaster Bujold
Hotel Grand Chancellor, Perth
Simon Oxwell, Grant Watson, Anna Hepworth, Daniel Oi, David Gunn, Colin Sharpe, Candice Schilder, Rick Jakins
Australian Guest of Honour: Tess Williams
Fan GoH: Gina Goddard
Rather than hold the convention over the Australia Day weekend, as was the tradition for non-Natcon Swancons, the decision was made to hold Swancon Twenty3 over the ANZAC Day weekend. This gave the committee an additional three months' lead-time to prepare the convention and publicise the event.
Swancon Twenty3 was the first of three Swancons to experiment with the concept of a "Dead/Posthumous Guest of Honour" - essentially a device to honour and discuss a particular speculative fiction writer/artist who was no longer alive. The first artist selected in this vein was 19th century French author Jules Verne. Local fan Damian Magee stood in for Verne at the opening ceremony, and even delivered a Guest of Honour speech in character. After the inclusion of Jim Henson in 2000 and Stanley Kubrick in 2001, the Dead Guest of Honour concept was discontinued.
In late 1997 British author Douglas Adams was approached about attending Swancon Twenty3 as a second International Guest of Honour, as he was expected to be in Australia at the time promoting the videogame Starship Titanic. While Adams initially agreed to appear, his participation in the convention did not ultimately eventuate.