Ten fire engines and around 70 firefighters were called to a hotel fire on Tooley Street near Tower Bridge.
Part of a room on the 10th floor of the building was damaged by fire. There were no reports of any injuries.
Station Commander Paul Morgan, who was at the scene, said: "Crews worked quickly to contain the fire and stop it from spreading further.
"Road closures were in place whilst firefighters made the scene safe and we asked people to avoid the area."
The Brigade was called at 1734 and the fire was under control by 1829. Fire crews from Dockhead, Old Kent Road, Lambeth, Bethnal Green, Dowgate and surrounding fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.