Leontius Pełczycki (secular name: Lewko Zenowicz or Zienkowicz, died in 1595) was a bishop in the Orthodox and Uniate Catholic churches in Lithuania.
In disputes about Orthodox benefices, the Bishop fought with Radziwills and the descendants of King Ivan Horodecki advocated on his side.
His work also assessed the patriarch of Constantinople Jeremias II, who in 1589, during his stay in the Grand Duchy of Lithuania, learned about the Bishop's tolerance of low morals among the clergy, including illegal re-canonical ordination of priests.
Jeremiah forbade the clergy exercise of worship and the bishop threatened to deprive Pełczycki of his office absent reform.
In June of this year, together with the bishops of Chelm, Dionysius (Zbyruyskyy), of Lutsk, Cyril Terlecki and Lviv, Hedeon Balaban he intended to convert to Catholicism while maintaining the Byzantine Rite.