Wiejca [ˈvjɛi̯t͡sa] is a village in the administrative district of Gmina Kampinos, within Warsaw West County, Masovian Voivodeship, in east-central Poland. It lies approximately 4 kilometres (2 mi) east of Kampinos, 22 km (14 mi) west of Ożarów Mazowiecki, and 35 km (22 mi) west of Warsaw.

South of Wiejca at 52°15′31″N 20°29′56″E / 52.25861°N 20.49889°E / 52.25861; 20.49889 (SLR Wiecja), there is a lattice tower used for radio relay links. This facility, whose Polish designation is SLR Wiecja, was used from 1974 to 1991 for the radio relay link between Warsaw and RCN Konstantynow.