Baltadvaris Castle () was a fortified manor house, earlier sometimes classed as a bastion castle, in lt:Baltadvaris (Molėtai), near Videniškiai in Molėtai district, Lithuania. The masonry castle with wooden fortifications was constructed by Swedish fortificators in the 16th century, in a bend of the River Siesartis, in order to secure the road from Vilnius to Riga against attacks from Livonia. It used to be the property of the princely Giedraičiai (Giedroyć) family. The neglected castle and fortifications gradually fell into ruins. Today only the foundations remain as well as parts of the walls and of the castle gates, together with several basementcellars.