Effingham is a town in Carroll County, New Hampshire, United States.

The town was settled by members of the Leavitt family of Hampton, New Hampshire, led by Captain John Leavitt, a soldier whose father, Moses, was a prosperous Hampton tavern keeper.

James W. Bradbury, later a U.S. senator from Maine, took charge of the school only on condition that it should be for the "instruction and training of teachers".

[1] Green Mountain, elevation 1,884 feet (574 m), is the highest point in town.

Province Lake lies partially within the town's borders to the south, and small portions of Ossipee Lake (Broad Bay and Berry Bay) are contained to the north.

The community is bounded on the east by the Maine state line, and on the north by the Ossipee River.

[7] The Ossipee River subwatershed, partially in Effingham, is home to the largest stratified-drift aquifer in New Hampshire.