Hallin Fell is a Lake District fell of 388 m in Westmorland and Furness. All four of its nearest neighbours are higher, up to Arthur's Pike at 533 m.
It is one of the 39 Wainwrights that are also Marilyns. Only 11 of the 242 hills profiled in England are lower. It is 263 m below the average height of the 103 register hills in Westmorland and Furness. The highest point is recorded as sw side of obelisk, not a cairn.