Fender's blue butterfly (Icaricia icarioides fenderi) is an endangered subspecies of Boisduval's blue (Icaricia icarioides) endemic to the Willamette Valley of northwestern Oregon, United States. The potential range of the butterfly extends from south and west of Portland, OR to south of Eugene, OR. The butterfly is host-specific on the Kincaid's lupine, which it relies on for reproduction and growth.