Siejkowo [ɕɛi̯ˈkɔvɔ] is a settlement in the administrative district of Gmina Ryn, within Giżycko County, Warmian-Masurian Voivodeship, in northern Poland. It lies approximately 4 kilometres (2 mi) south of Ryn, 20 km (12 mi) south-west of Giżycko, and 71 km (44 mi) east of the regional capital Olsztyn.