It comes after police were called to Victoria Road at 4.55pm on March 6 with reports of a stabbing.
At the scene, the 16-year-old victim was found suffering from stab wounds and was taken to hospital.
His condition has been described as critical and his family are receiving support from specialist officers.
A 19-year-old man has been arrested.
Det Insp Tony Smith said: “We recognise this is a distressing incident and we have upped local foot patrols and will ensure there is a visible police presence over the weekend.
“Although we have a suspect in custody, we are working round the clock to build a picture of what happened and I would ask anyone with information to contact us immediately.”
Victoria Road remains closed from the junction with Stonefield Way to the Field End Road roundabout as the crime scene still stands.
READ MORE: Male fighting for his life in hospital after stabbing in Ruislip
Police ask that anyone with information that could help the investigation contacts them on 101 or via @MetCC on X quoting reference 5631/06Mar.
Anyone who has dashcam, CCTV or doorbell footage of an assault should also report this.
Crimestoppers can be contacted anonymously on 0800 555 111.
