Green Island is a residential neighborhood on the south end of La Crosse, Wisconsin. It is located on an island with only one road to the mainland, 7th Street South. The island is by Swift Creek and Bluff Slough on the east, Mormon Slough on the south, Sand Slough and the Mississippi River main channel on the west, and a small channel on the north side of the island. This small channel has been filled in over the years, and all that remains today is a large culvert with some bridge-like guard rails.

Green Island is prone to flooding, and has a major flood on an average of once per decade.