波雅尔英文写作boyar或bolyar (保加利亚语：боляр or болярин; 乌克兰语：буй or боярин; 俄语：боя́рин，罗马化：boyarin，IPA：[bɐˈjarʲɪn]; 罗马尼亚语：boier, IPA：[boˈjer]; 希腊语：βογιάρος),是封建时代保加利亚帝国、莫斯科大公国、基辅罗斯、 瓦拉几亚和摩尔多瓦的一个仅次于大公的贵族头衔。由10-17世纪，在保加利亚、俄国和罗马尼亚演变为表示仅次于沙皇的亲王王子，加在姓氏前面是“采邑贵族”，在芬兰写作 Pajari 以显示和“食邑贵族”的区别。

A boyar was a member of the highest rank of the feudal Bulgarian, Moscovian, Kievan Rus'ian, Wallachian, and Moldavian aristocracies, second only to the ruling princes (in Bulgaria, tsars), from the 10th century to the 17th century. The rank has lived on as a surname in Russia, Ukraine and Romania, and also in Finland, where it is spelled Pajari.