Otter Lake is an unincorporated community and census-designated place (CDP) in Steuben County, Indiana, United States.

[2] The community is in western Steuben County, surrounding Otter Lake, a natural water body.

U.S. Route 20 forms the northern edge of the CDP; the highway leads east 9 miles (14 km) to Angola, the county seat, and west 13 miles (21 km) to LaGrange.

Indiana State Road 327 forms the western edge of the community, leading north 6 miles (10 km) to Orland and south 21 miles (34 km) to Garrett.

[1] The lake's outlet is at its northern end, flowing into Pigeon Creek, which becomes the Pigeon River, a west-flowing tributary of the St. Joseph River leading to Lake Michigan.