Aero Flight 217 was a domestic passenger flight from Helsinki, Finland, to Mariehamn in the autonomous territory of Åland, operated by the Finnish flag carrier Aero O/Y. On 8 November 1963, the aircraft serving the flight crashed in poor visibility while attempting to land on a non-precision approach at Mariehamn Airport in the municipality of Jomala, resulting in the deaths of 22 people out of 25 on board. The crash remains the second most deadly aviation accident in Finland, the first being Aero Flight 311 almost two years earlier.

Mariehamn is the capital of Åland, an autonomous territory under Finnish sovereignty. Mariehamn 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 Lemland. Like all of Åland, Mariehamn is unilingually Swedish-speaking and around 82% of the inhabitants speak it as their native language.