Graf Jurgis Konstantinas Broel Pliateris (Polish: Jerzy Konstanty Broel-Plater; 1810–1836) was a bibliographer and researcher of the Lithuanian language and literature.

He collaborated with several researchers, including Simonas Stanevičius whom he employed as his secretary and librarian and professor Ludwig Rhesa.

[6] The baptismal record also revealed that Pliateris was born in Memel (Klaipėda) which was then part of East Prussia and not in his family's estate in or near Švėkšna as previously assumed.

[2] Pliateris inherited about 3,400 hectares (8,400 acres) of land[5] with a manor in Gedminaičiai [lt] from his parents and started organizing his library there.

[2] He supported education of the peasants and planned to establish schools that would teach according to the method developed by Joseph Lancaster.

As a young man, Teodoras fell off a horse, hit his head, and became mentally disabled requiring assistance until his death at the age of 66.

In 1833, Pliateris financed the publication of Pažymės žemaitiškos gaidos (Notes of Samogitian melodies), a collection of sheet music for Lithuanian folk songs prepared by Stanevičius.

[2] In a short time, Pliateris wrote several studies on the Lithuanian language, though due to his early death many were left unfinished and none were published during his lifetime.

[2] His Polish-language bibliographical work Materiały do historyi literatury języka litewskiego (Sources for the history of the Lithuanian language) was left unfinished.

[2] Pliateris collected books, schematic plans of thirteen castles, portraits of the nobility, weapons (shields made of European bison skin), numismatic and archaeological artifacts, etc.

The library had copies of Postil of Mikalojus Daukša (1599), Polish–Latin–Lithuanian dictionary by Konstantinas Sirvydas, unpublished manuscript by Simonas Daukantas, Lithuanian sermon delivered on the occasion of the death of King Sigismund III Vasa in 1632, etc.

Many items were lost during World War I; six boxes and a bag of most valuable books and documents were hidden by a local priest.