Selaön is the largest island in Mälaren, Sweden, and covers 95 km². It is located at Stallarholmen, east of Strängnäs, and it has about 3,000 permanent residents. It is connected by a bridge to the mainland. It is the largest island in any lake in Sweden. In the Heimskringla, Granmar, the king of Södermanland, was murdered on this island by Ingjald Illruler.

Selaön is the largest island in Mälaren, Sweden, and covers 95 km². It is located at Stallarholmen, east of Strängnäs, and it has about 3,000 permanent residents. It is connected by a bridge to the mainland. It is the largest island in any lake in Sweden. In the Heimskringla, Granmar, the king of Södermanland, was murdered on this island by Ingjald Illruler.