Eliza Island is located in the western part of Bellingham Bay in the U.S. state of Washington. It lies just east of the southern part of Lummi Island, in Whatcom County. Eliza Island has a land area of 0.571 km² (0.220 sq mi; 141 acres). Its population was ten persons as of the 2010 census^[update].

The island was named by Charles Wilkes during the Wilkes Expedition of 1838–1842. One of the few names given by Wilkes that does not honor either members of his crew or American naval officers, Eliza refers to Francisco de Eliza, the Spanish commander of a 1791 expedition to the Pacific Northwest. Wilkes may have named the island for his daughter or his sister, both named Eliza.^[1][2]

The south end of Eliza island is home to commercial and recreational crabbing.

Eliza Island has a small airstrip that can only be used during daylight hours, and one dock which is used strictly for loading and unloading. There is no scheduled ferry service to the island, although private charters can be hired for residents. It is a private island with only about five people who live there year-round. Private generators provide electricity, and a communal water desalinization system is used to provide water to the residents. Only people who are 25 or older or disabled are allowed to use golf carts; although most residents travel by foot. A designated swimming beach on the south side of the island is sandy and somewhat shallow.