The Horn is a mountain located in Coos County, New Hampshire.

The south face of the Horn drains into the headwaters of the West Branch of the Upper Ammonoosuc River.

The northwest face of the Horn drains north, thence into the West Branch of Mill Brook, and into the Upper Ammonoosuc.

Unknown Pond lies to the northeast of the mountain and provides an excellent view of the peak.

The open ledges on the summit face west, however, so it is difficult to see the pond from the top of the mountain.