San Nicolas Island is the most remote of California's Channel Islands. "San Nic" or "SNI" was originally the home of the Nicoleņos people.

The Nicoleņos were evacuated in the early 19th century by the padres of the California mission system after a series of attacks of conflicts with Aleutian and Russian hunter-traders. Within a few years of their removal from the island, the Nicoleņo people and their unique language became extinct.

The most famous resident of San Nicolas Island was "The Lone Woman of San Nicolas Island" also known as "Juana Maria." Her real name was never known to anyone on the mainland. She resided on the barren island alone for 18 years before she was found by a sea-otter hunter in 1853. Brought back to the Santa Barbara Mission, she died within weeks, her system unprepared for the different nutritional and environmental conditions in central California. Her story was the basis for Scott O'Dell's Newbery Medal-winning 1961 novel Island of the Blue Dolphins.

San Nicolas Island is currently controlled by the United States Navy and used as a weapons testing and training facility.