Nootka Sound, inlet of the Pacific Ocean and natural harbor on the west coast of Vancouver Island, SW British Columbia, Canada, lying between the mainland and Nootka Island (206 sq mi/534 sq km). The mouth of the sound was sighted (1774) by Juan Pérez, the Spanish explorer. The sound itself was visited by Capt. James Cook (1778), who was the first European to land in that region. John Meares, the British explorer, established a trading post on Nootka Sound in 1788. Its seizure by Spaniards in 1789 became the subject of a controversy between Spain and England over claims in the region. The Nootka Convention (1790) resolved the dispute and opened the N Pacific coast to British settlement.