The Osse Stream or Osse Ditch, otherwise known as the Appleton Brook, is a small stream in the Vale of White Horse in Oxfordshire (historically in Berkshire).
The stream is a tributary of the River Ock, with its confluence near Marcham Mill. The stream rises at a pond in Cumnor, flowing past Besselsleigh, Appleton, Fyfield, Frilford and Marcham.
The hydronym Osse appears to be derived from the Old English word Wase, meaning 'mud'.