Jagiс Ignatius (Vatroslav) (1838‒1923) – philologist, specialist in Slavic studies, linguist, paleographer, and archeographer.

He studied at the Philosophical Faculty of the University of Wien, taught at the Zagreb Gymnasium. In 1866, he was elected for Members of the South-Slavic Academy of Sciences and Arts. Academician of the St. Petersburg Ac. of Sc. in the Department of Russian Language and Literature (1869). He made lectures in comparative grammar of Indo-European languages and Sanskrit at the Novorossiisk University (1872-1874), in Slavic philology at the Berlin University (1874-1880), in Church Slavic and Russian languages at the St. Petersburg University (1880-1886) – also he made lectures ate the Higher Female Courses and at the Archeological Institute. Professor of the University of Wien (1886-1908).

One of the greatest experts in the field of Slavic linguistics of the second half of the nineteenth and early twentieth centuries.