Alfred Theophil Holder (4 April 1840 – 12 January 1916) was an Austrian philologist, historian, and librarian. A specialist of Latin literature and Roman history, he is best known for his editions of Horace, Caesar, Tacitus, and Avianus, as well as for his three-volume lexicon of ancient Celtic languages entitled Alt-celtischer Sprachschatz (1891–1913).[1][2]