Konstantynów [kɔnstanˈtɨnuf] is a village in Płock County, Masovian Voivodeship, Poland with population of 38 people. It lies approximately 6 kilometres (4 mi) south-east of Gąbin, 22 km (14 mi) south of Płock, and 84 km (52 mi) west of Warsaw.
From 1974 to 1991 the tallest ever manmade structure stood here, the Warsaw radio mast. This mast was a 646.38-metre-high (2,120.7 ft) guyed radio mast in steel-framework construction with triangular cross section with a side length of 4.8 metres and a weight of 420 tons. The mast was used for the 2000 kilowatt long wave transmitter of the Polish broadcasting authority as aerial and was therefore insulated against ground for a voltage of 120 kilovolts. It collapsed during renovation work on August 8, 1991. Nobody was reported killed in the accident.