The star will be joined by big name international guests, including Anthony Mackie, Isaac Hempstead Wright, Nolan North and Troy Baker.
Comic Con Africa will take place at Gallagher Convention Centre in Midrand from September 21-24. Tickets for the event cost R160 a day or R500 for a four-day pass.
William fell in love with Mzansi a long time ago and filmed a new mini-series in Cape Town. He tweeted a series of pictures of the city as he gushed over our beautiful land.
He also visited the country in 2012 when he shot an advertisement for local insurance company Dial Direct.
William has authored several books about his time as Captain Kirk and the Star Trek Universe. He has also co-written several novels set in the Star Trek universe.