The emergency services were called to the A10 High Road outside South Tottenham Overground station around 5am today (August 8).
Paramedics treated the biker for a leg injury and took him to hospital “as a priority”.
His injuries have been deemed to be potentially life-changing.
The driver of the other vehicle, a van, stopped at the scene and is helping with the investigation.
The A10 remains closed by police.
A Metropolitan Police spokesperson said: “Police were called at 04:57hrs on Friday, 8 August following reports of a collision involving a car and a motorcycle.
“The motorcyclist was taken to hospital. His injuries have been deemed as potentially life-changing.
“The driver of the car stopped at the scene and is assisting officers with enquiries.
“Officers remain at the scene.”
A London Ambulance Service spokesperson said: “We were called at 4.43am today (8 August) to reports of a road traffic collision in High Road, Tottenham.
“We sent an ambulance crew and paramedics in fast response cars to the scene.
“We treated a patient for a leg injury and took him to a major trauma centre as a priority.”
