Walerian Protasewicz (also: Protaszewicz-Szuszkowski, Lithuanian: Valerijonas Protasevičius; c. 1505 – 31 December 1579 in Vilnius) was bishop of Lutsk (1549–1555) and Vilnius (1555–1579). Born to a family of petty Ruthenian nobles (szlachta), Protasewicz worked as a scribe, notary, and secretary at the chancellery of the Grand Duchy of Lithuania until his appointment of bishop. He was politically active and was one of the lead Lithuanian negotiators for the Union of Lublin in 1569. He neglected religious matters and allowed the Reformation to spread. In the last decade of his life, he invited the Jesuits to the Grand Duchy of Lithuania and funded the Jesuit college in Vilnius. He obtained papal and royal privileges to convert the college into Vilnius University in 1579. He donated his per