Valdes Island is located in the Southern Gulf Islands, across Porlier Pass from Galiano Island, between Vancouver Island and the British Columbia mainland.

The island supports a small community of residents at Starvation Bay on the north shore, but the majority of the population of the island consists of part-time vacationers. A third of Valdes Island is a First Nations Reserve for the Lyackson First Nation at Shingle Point.

The Lyackson First Nation is a small, Central Coast Salish Hulq’umin’um community of fewer than 200 members presently based in Chemainus on Vancouver Island. There are approximately 60 archaeological sites on the island, evidence that First Nations People have used the island for nearly 5,000 years. Visitors are requested to respect Native property and the sacred and protected archeological sites and burial grounds on the island.

Valdes Island is named after the Spanish naval officer Cayetano Valdez y Bazan, who first visited the area in 1792 as a lieutenant serving under Captain Alexandro Malaspina on the Descubierta. Valdes returned in 1792 as captain of the Mexicana to explore the area with Captain Dionisio Galiano aboard the Sutil. Valdes and Galiano both commanded warships captured by the British in the Battle of Trafalgar.

The island covers an area of 9 square miles (23 square kilometres), and is 1 mile (1.6 km) wide and 10 miles (16 km) in length. Aside from a short stretch of beach at the southern end of the island near Porlier Pass, Valdes Island is surrounded by steep cliffs and deep water.

There are no water or electrical services on the island, and roads are restricted to forestry logging roads.