With approximately 4.5 million residents in the metro area, sprawling and prosperous Johannesburg is the largest city in South Africa, and although it doesn't have as visible a GLBT population as Cape Town, it is home to a growing and increasingly visible gay community, and the city hosts the largest and oldest Pride celebration in South Africa (and, in fact, on the continent), having drawn some 17,000 participants in recent years.
Johannesburg Gay Pride is held each year in late October. The date this year is October 29, 2016.
The city's massive Gay Pride celebration takes place on Saturday, the 29th, at Melrose Boulevard, Melrose Arch, and kicks off with a Johannesburg Gay Pride Parade at 4:30 pm (although gates open at 2 pm for the festival). The celebration continues throughout the day includes live music, DJs, food, drinks, and other fun.
Note that Cape Town, South Africa Gay Pride takes place in late February and early March each year. It's also a favorite with visitors from all over the world.
Johannesburg Gay Resources
For more tips on GLBT travel in Johannesburg, you can have a look at South Africa's very reliable gay newspaper and website Exit as well as the In Your Pocket Johannesburg Gay Guide. Also be sure to visit the travel site run by Joburg Tourism, the city's official travel site, where you'll find plenty of great information about visiting the city and region.
If you're going to be traveling in other parts of the country, look to the South Africa Tourism official web page, which has lots of tips and recommendations on visiting all of South Africa.