The victim was attacked on Wood Green Road just before 1am.
He was treated by paramedics at the scene before being taken to hospital.
A spokesman for West Midlands Ambulance Service said: "We were called at 0.55am on Tuesday morning to reports of a stabbing on Wood Green Road, Wednesbury.
"An ambulance and a paramedic officer attended and found one man who had sustained a serious injury.
"He was given trauma care on scene before being conveyed to hospital for further treatment."
West Midlands Police have been approached for comment.
