Mariehamn is the capital city of Åland.

Mariehamn is an autonomous territory under Finnish sovereignty. It is the seat of the Government and Parliament of Åland, and 40% of the population of Åland live in the city. It is mostly surrounded by Jomala, the second-largest municipality in Åland in terms of population; to the east, it is bordered by Leland. Like all of Åland, Mariehamn is unilingually Swedish-speaking and around 88% of the inhabitants speak it as their native language.

The theme of the coat of arms of Mariehamn refers to the city's main livelihood, maritime transport, and the city's parks, which are typically lined with linden trees. The coat of arms was designed by Nils Byman and confirmed in 1951.