[4] It comprises the same area as the administrative Östergarn District, established on 1 January 2016.

[5] Östergarn is situated on a peninsula on the central part of eastern Gotland.

[8] As of 2019[update], Östergarn Church belongs to Östergarn parish in Romaklosters pastorat, along with the churches in Gammelgarn, Kräklingbo, Anga and Ala.[9][10] The harbor village Katthammarsvik is on the north coast of Östergarn and the Herrvik fishing village is on the eastern tip of the peninsula.

About 4 km (2.5 mi) northeast of Herrvik is the Östergarnsholm island with its two lighthouses.

[6] Along the southern coast is the Sandviken Natura 2000 nature reserve with its long, sandy beach.