Mystic is located in New London County. As of the 2000 census,  the total population was 4,001. The town is actually split between Stonington and Groton, divided by the Mystic River.

Historically a leading seaport of the area, the story of the town's nautical connection is told at the Mystic Seaport, the world's largest maritime museum, which has preserved both a number of sailing ships (most notably the whaler Charles W. Morgan) and the seaport buildings ashore. The town is located on the Mystic River, which flows into Long Island Sound, providing access to the sea. The Mystic River Bascule Bridge crosses the river in the center of town.

A major New England tourist destination, the town is also home to the Mystic Aquarium & Institute for Exploration, notable for its research department, dedication to marinelife rehabilitation and not capitivity, and its popular beluga whales.

 A tourist area with gift shops and eating establishments lines Main Street on either side of the bascule bridge over the Mystic River. The town is famous for it's annual art festival in August, and it's newer "taste of Connecticut" in September. It is a lively little town , with events offered all year round.

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The 1988 film, Mystic Pizza, was filmed in the town. It is set at a restaurant of the same name, which is still open and popular with tourists.