Lake Mills was a reservoir in Olympic National Park, Washington, United States, that existed from 1927 to 2012.

The lake was formed in 1927 with the completion of the dam and after the lowland forest that occupied the river bottom was clear-cut.

The Elwha Ecosystem Restoration project included the removal of the Glines Canyon Dam in 2014.

The lake was fully drained by October 2012, leaving only sediment upstream of the former dam site.

Olympic National Park crews are revegetating the area to speed up ecological restoration and improve the habitat for the return of the salmon.