The first Sean-nós NW Festival was held in Portland, Oregon in 2008, and was a small one-day event organized by Portland singer David Ingerson, featuring Seán Williams (singing) and Maldon Meehan (dancing).  Since then, the festival has grown significantly and alternated between Portland and Olympia, Washington.  Sean-nós NW was organized as a Washington State nonprofit corporation in 2009 by founding Board members Seán Williams, David Ingerson, Maldon Meehan, Alicia Guinn, Kimberly Goetz, and Graham Smith.

In 2014, the Irish Cultural Society of the Pacific Northwest took over the responsibility of running the festival.