Lietuvinink (Lithuanian: Lietuvininkas, plural - Lietuvininkai) is a Lithuanian from Lithuania Minor. Unlike other Lithuanians, who were mostly Roman catholic in late medieval, Lietuvninks were mostly Lutherans. Lithuania Minor (or Prussian Lithuania, Lithuanian Mažoji Lietuva and Prūsų Lietuva respectively) is one of five ethnographic regions of Lithuania. ... The Roman Catholic Church, most often spoken of simply as the Catholic Church, is the largest Christian church, with over one billion members. ... The Lutheran movement is a group of denominations of Protestant Christianity by the original definition. ...

It is argued sometimes that the term Lietuvininkas basically meant just Lithuanian in Lithuania Minor; and that at the start there were two names to name Lithuanians, "lietuvis" and "lietuvininkas", the first of which, "lietuvis" (now translated as Lithuanian) became popular in other regions of Lithuania, while "Lietuvininkas" became popular in Lithuania Minor. Neverless, now the term Lietuvinink means solely a person from Lithuania Minor rather than Lithuanian in general.