Gigartina agardhii
- kingdom: Plantae
- phylum: Rhodophyta
- class: Florideophyceae
- order: Gigartinales
- family: Gigartinaceae
- genus: Gigartina
- species: Gigartina agardhii
Sooke
British Columbia
CanadaSitka
AlaskaCarmel-by-the-Sea
La Jolla
Montara
Moss Beach
Pacific Grove
Pacifica
California
United States