Siekluki [ɕɛˈkluki] is a village in the administrative district of Gmina Dzierzążnia, within Płońsk County, Masovian Voivodeship, in east-central Poland. It lies approximately 5 kilometres (3 mi) east of Dzierzążnia, 6 km (4 mi) west of Płońsk, and 66 km (41 mi) north-west of Warsaw.