Alger Island, also known as Big Island, is a small island located on Fourth Lake, part of the Fulton Chain of Lakes, within the Adirondack Park in New York State.

The island is located in the Town of Webb, in Herkimer County, New York.

Alger Island was purchased by the state of New York on January 16, 1950.

Today, the island is operated as a state campground, managed by the New York State Department of Environmental Conservation.

This article about a location in Herkimer County, New York is a stub.