Town (pop., 2004 est.: 6,570), administrative centre of the Shetland Islands, northern Scotland. It is on the eastern coast of the island of Mainland. Britain's northernmost town, it originated as a fishing village and is notable for its herring catch. The North Sea oil boom of the 1970s increased port traffic, and Lerwick became an oil supply and service base. It is the seat of the Shetland Islands council area.