French Island is a census-designated place (CDP) in La Crosse County, Wisconsin, United States.

All of the island is part of the La Crosse Metropolitan Statistical Area.

French Island is located in western La Crosse County.

It is surrounded by waterways connected to the Mississippi River: French Slough, French Lake, and Lake Onalaska to the west, and the Black River and Richmond Bay to the east.

The neighborhood of West La Crosse is in the southern part of the CDP.

The island is accessible from the mainland by automobile, by way of the I-90 Mississippi River Bridge and from North La Crosse via the Clinton Street Bridge at the extreme southern end of the island.