Six fire engines and around 40 firefighters attended a fire on Walworth Road in Camberwell.
Part of a flat on the third-floor of a mixed-use building was damaged by fire. There were no reports of any injuries.
The Brigade received the first of 10 calls at 2049 and Control Officers mobilised crews from Peckham, Old Kent Road, Lambeth, Brixton and Dowgate fire stations to the scene. The fire was brought under control by 2126.
The fire is believed to have been accidental and caused by the ignition of hot oil on a cooking hob.
A London Fire Brigade spokesperson said: "Take extra care when cooking with hot oil as it can easily overheat and catch fire.
“Never fill a pan more than one third full of fat or oil and make sure food is dry before putting it in hot oil – oil and water are a dangerous mix.
“If the oil starts to smoke, it’s too hot so turn off the heat and leave it to cool. We also advise using an electronic deep fat fryer if possible – they have automatic temperature controls and are much safer.
"It's also really important to keep the hob, cooker hood and extractor fan clean too – built up fat and grease can ignite and cause a fire."