Westham Island is an island located near Ladner, British Columbia, Canada within the City of Delta, which in turn is part of Greater Vancouver, Canada. The George C. Reifel Migratory Bird Sanctuary for migratory birds is located at the northern end of the island, home to over 300 bird species. Every year in October, almost 85,000 Lesser Snow Geese arrive as they travel from Wrangel Island to the Atlantic.^[1] The Alaksen National Wildlife Area is also located on the island.

The Westham Island Swing Bridge was built to connect the island to Ladner, and was opened on March 29, 1910, and is one of the oldest bridges in BC. A rehabilitation of the bridge was completed in 2010.^[1]

The island was named by Harry Trim who came from Westham, Sussex.^[2]: 292