A WA teenager is in a critical condition following a stabbing in Scarborough, northwest of Perth.

The 15-year-old was allegedly injured in a brawl with about 15 people, where one person was allegedly carrying a knife.

It has been reported by the West Australian that the alleged attack occurred at The Esplanade about 3.50pm.

Know the news with the 7NEWS app: Download today

Paramedics treated the teenager at the scene before transporting him to Royal Perth Hospital.

An adult was also treated at the scene for minor injuries.