ENThe article is devoted to analyzing the participation of magnates in Lithuanian assemblies during the reign of Augustus III (1735–1763). The magnates of the reign of August III include the families: Radziwill, Sapieha, Czartoryski (related to them Massalski and Jerzy Flemming), Oginski, Pociej and Sollohub. Magnates rarely attended sejmiks and mainly acted on it from behind the scenes with the help of their supporters rather than through personal participation. During the reign of August III, it was possible to reveal 110 examples of direct participation of magnates in parliamentary or deputy assemblies. Magnates mainly went to deputy assemblies to be elected deputies to the Sejm of the Commonwealth. Of these, 65 magnates were successful and were elected deputies. Nineteen more magnates were at thunderous assemblies, where they were elected deputies to the Lithuanian Tribunal. Twenty- six more magnates were elected directors at sejmiks: deputies (8 times) and Candlemass sejmiks (18 times). Keywords: magnate, nobility, sejmiks, the Radziwills, the Sapiehas, the Massalskis, the Czartoryskis, the Oginskis, the Pociejs, the Sollohubs.