Borgholm is a city and the seat of Borgholm Municipality, Kalmar County, Sweden with 4,401 inhabitants in 2020. It is located on the island of …Borgholm is a city and the seat of Borgholm Municipality, Kalmar County, Sweden with 4,401 inhabitants in 2020. It is located on the island of Öland in the Baltic Sea, at the Kalmar Strait-side of Öland, north of Färjestaden.