The women's 100 metres event at the 1999 All-Africa Games was held 14–15 September 1999 at the Johannesburg Stadium.
[1] Qualification: First 2 of each heat (Q) and the next 6 fastest (q) qualified for the semifinals.
Qualification: First 4 of each semifinal (Q) qualified for the final.
Wind: +0.1 m/s