The Gulf Islands are the islands in the Strait of Georgia (also known as Salish Sea or the Gulf of Georgia), between Vancouver Island and the mainland of British Columbia, Canada.
According to BC Geographical Names (BCGNIS) the name "Gulf Islands" was originally intended and commonly understood to refer to the archipelago at the southern end of the Strait of Georgia—from Gabriola Island in the north to Saturna Island in the southeast and D'Arcy Island in the southwest. During the 1990s, however, the name began to be applied to all the islands in the Strait of Georgia, resulting in the introduction of the term "Southern Gulf Islands", which BCGNIS calls a misnomer, to distinguish the original "Gulf Islands" from the rest, which are sometimes called the "North Gulf Islands". BCGNIS further notes that Quadra Island is increasingly described as the "northernmost of the Gulf Islands".
The division of the Gulf Islands into two groups, the Southern and Northern Gulf Islands, is relatively common. The dividing line is approximately that formed by the city of Nanaimo on Vancouver Island, and the mouth of the Fraser River on the mainland. The larger populated islands are served by BC Ferries, which operates various vehicle and passenger ferries between the Gulf Islands and to terminals near the major cities of Nanaimo and Victoria on Vancouver Island as well as Vancouver on the mainland. BC Ferries distinguishes between the Southern Gulf Islands and the Northern Gulf Islands. Their Northern Gulf Islands includes both Quadra Island and Cortes Island, as well as some islands far to the north, such as Malcolm Island and Cormorant Island.Natural Resources Canada maps the Gulf Islands as including the "Southern Gulf Islands", the islands of Howe Sound (such as Bowen Island, Gambier Island, and Keats Island), along with Lasqueti Island, Hornby Island, and Denman Island.