Marstrand is a seaside locality situated in Kungälv Municipality, Västra Götaland County, Sweden. It had 1,320 inhabitants in 2010. The town got its name from its location on the island of Marstrand. Despite its small population, for historical reasons Marstrand is often referred to as a city. The city had free port status, which was declared by King Gustav III, from 1775 to 1794.