Gabriola is part of the traditional territory of the Snunéymux, and the name of the nearby city, Nanaimo, is an anglicized form of their name. The earliest archaeological record on Gabriola is a cave burial dated to about 1500 BCE, but sites on nearby Valdes Island and other Gulf Islands have been found to date to at least 3000 BCE.
The pre-contact population of Gabriola has been difficult to estimate, but in mid-Marpole times—between about 0 and 1000 CE—several thousand people lived in the village at False Narrows, the site of today's El Verano Drive. Archaeologists have found that infant mortality at that time was surprisingly low and that the population was well adapted to its environment. Other smaller villages on Gabriola were scattered around the coast. After contact, and perhaps as early as 1500 CE, the population of the Snunéymux declined drastically because of smallpox and other diseases brought to North America by Europeans.
The island is famous for its petro glyphs, which are commonly asserted to be thousands of years old. The reality is that they are almost impossible to date. Because they are carved in relatively soft sandstone, they are eroding rapidly