Austrian scholar; born at Tarnow 1859. He studied Bible and Talmud up to the age of eighteen, then academic subjects at the Jewish Theological Seminary of Breslau and at the gymnasium of Bielitz, and subsequently Germanic philology, especially English, at the University of Vienna (Ph.D. 1884). In 1890 he became privatdocent in English philology at the University of Vienna, being at the same time professor at a "Realschule" in Vienna. In 1904 he was appointed assistant professor of English language and literature at the University of Czernowitz.
Kellner's works include an edition of Caxton's "Blanchardyn and Eglantine" (for the Early English Text Society), 1890; "Historical Outlines of English Syntax," London, 1892; "Shakespeare," Leipsic, 1900; "Ein Jahr in England," Stuttgart, 1900; and a new edition of Thieme's "Englisches Wörterbuch," Brunswick, 1903.