Annacis Island is a narrow island under the jurisdiction of City of Delta in Lower Mainland, British Columbia, located just downstream of the south arm of the Fraser River bifurcation between Lulu Island to the north and the Delta peninsula to the south.
The island is now mostly an industrial zone, and contains one of Metro Vancouver's secondary wastewater treatment plants, the Annacis Island Wastewater Treatment Plant.
Connections northward to Richmond and New Westminster are via smaller bridges on Highway 91.
Annacis Island is served by a public bus that connects to 22nd Street Station in New Westminster.
[3] The island's name is derived from "Annance's Island," named for Noel François Annance, an Abenaki and a Hudson's Bay Company clerk, who travelled with Chief Factor James McMillan to found Fort Langley in 1827.