[3] Traditionally on the northern fringes of the historic County of Dunbartonshire, it is on the banks of Loch Lomond, and has a pier.

The village of Arrochar stands at the head of Loch Long, at the other side of the isthmus.

Arrochar and Tarbet railway station, on the West Highland Line, stands between the two villages.

Its name comes from the Scottish Gaelic word for isthmus, although Tarbert is the more common anglicization, and Tarbat also exists.

The area around Arrochar and Tarbet has become the scene of "squirrel wars".