Emergency services were called to Yesnaby on the west of the island shortly after 5.30am on Saturday to reports that a vehicle had gone over the cliffs.
Stromness Lifeboat searched the area and found the vehicle submerged in water.
It is as of yet unclear whether or not anybody was inside the vehicle.
The lifeboat crew said in a statement: “A vehicle was located in deep water out of reach of the crew.
“A search was then carried out of the surrounding cliffs and beaches with nothing found.”