A Crime scene remains in place and a teenager who is understood to be 15 years old was treated by Paramedics at the scene.
He has since been taken to Croydon University Hospital.
The Colonnade bus stand was closed by police and a crime scene was established
A Spokesman for the Met Police said: Police were called at about 5:40pm on Monday, 8 May to reports of an assault at The Colonnades in Croydon.
Officers attended and found a male, believed to be aged 15 years old, suffering from a stab injury. He was taken to a South London hospital for treatment; his injury is not believed to be life-threatening.
There have been no arrests and enquiries continue.