The incident happened in Stafford Road just after 3.10pm today (December 24).
Officers and London Ambulance Service crews attended and found a man injured.
He was treated at the scene before being taken to hospital where his condition is unknown.
It is unknown which supermarket the incident took place.
No arrests have been made as police enquiries continue.
A spokesperson for Metropolitan Police said: “Police were called to a supermarket in Stafford Road, Wallington, at 15.11hrs on Sunday, 24 December to reports of a stabbing.
“Officers attended. A 27-year-old man was found with stab wounds. He was treated at the scene by paramedics before being taken to hospital.
“We await an update on his condition.
“A crime scene has been put in place. There have been no arrests.”
https://www.thisislocallondon.co.uk/news/24010950.stafford-road-wallington-stabbing-man-taken-hospital/
