Dr Zahid Badroodien, Cape Town’s MMC for Water and Sanitation, said the blaze was contained just before 9pm on Saturday night.
“It is estimated that about 100 structures are damaged,” said Badroodien.
He said the fire and emergency services had stayed on scene at the Joe Slovo informal settlement to deal with any flare-ups of the flames.
The fire was reported just before 6pm.
Badroodien said 12 fire engines and four water tankers were deployed to deal with the blaze. It took hours to extinguish the flames.
A video from GroundUp showed residents forming a chain with buckets of water, desperately trying to douse the flames.
Others were frantically trying to salvage what they could from their belongings before the fire caught their home. Some could be seen just standing on their roofs and surveying the damage being done.
The cause of the fire is unclear. No injuries or deaths have been reported.
The South African Social Security Agency (Sassa) was also at Langa to assess how many families are affected by the fire and what aid is needed to help those that lost their homes.