Alfred Theophil Holder (4 April 1840 in Vienna – 12 January 1916 in Karlsruhe), was chief librarian of the Baden State Library (Badische Landesbibliothek) in Karlsruhe.
He was an Austrian-German writer and student of several ancient languages including Celtic, Germanic, and Latin.
He is best known for his translations of Horace, Caesar and Tacitus as well as for his three volume Celtic vocabulary entitled: Alt-celtischer Sprachschatz.
He studied classical and German philology at the universities of Bonn and Heidelberg, then continued his education in Paris.
From 1863 he worked as a schoolteacher in Rastatt, the Netherlands and in Ladenburg.
In 1867 he joined the Grand Ducal Baden Court and State Library in Karlsruhe, where he remained for the rest of his life — in 1904, he became head of the manuscript department and in 1911 was appointed director.