Zełwągi [zɛu̯ˈvɔnɡi] is a village in the administrative district of Gmina Mikołajki, within Mrągowo County, Warmian-Masurian Voivodeship, in northern Poland.

This small village occupies a disproportionately prominent place, compared to its size, in the history of the Church of Jesus Christ of Latter-day Saints in Europe, since it was here that the first meeting-house of the Church in continental Europe was built, in 1929.

Services continued to be held in German until this practice was forbidden by the Polish government in 1947.

Most of the members who had not died in the war or were expelled shortly afterwards left in the succeeding years, due to the poor economic conditions in the area.

Some remaining members from Zełwągi contributed to signature drive of the petition to register the Church of Jesus Christ of Latter-day Saints in Poland in 1977.