Police were called to Hazel Grove, junction with Sydenham Road, at 7.19pm on Saturday, 10 April after reports of a male lying injured on the ground.
Officers attended with medics from the London Ambulance Service and the London Air Ambulance. They found a 17-year-old male who had been stabbed.
Despite the best efforts of the emergency services, he was pronounced dead shortly after 8pm. His next of kin have been informed.
A crime scene is in place and the public can expect to see an increased police presence in the area in the coming hours.
Anyone who witnessed the incident is urged to call 101, providing the reference CAD6072/10APR.
Information can also be provided to Crimestoppers, anonymously, by calling 0800 555 111.
Hard calls save lives. Are you close to someone on the fringes of knife crime? Do the right thing, please give information 100 per cent anonymously through the independent charity Crimestoppers. It can feel like a hard call, but it could save the life of someone you love.
No piece of information about knife crime is insignificant or too small. Any information you give to Crimestoppers can make a difference in reducing knife crime and the harm it causes to families.
They never ask your name and they cannot trace your call, your IP address or the device you use. Fill in their quick online form or call 0800 555 111. It could save a life.