Marianów Sierakowski [maˈrjanuf ɕɛraˈkɔfski] is a village in the administrative district of Gmina Gostynin, within Gostynin County, Masovian Voivodeship, in east-central Poland. It lies approximately 8 kilometres (5 mi) south-west of Gostynin and 110 km (68 mi) west of Warsaw.