Theodor Gartner (4 November 1843 — 29 April 1925) was an Austrian linguist, Romance philologist and professor.
Living among Ukrainians, he got interested in their language, first of all in grammar, phonetics and vocabulary.
In co-authorship with Smal-Stotsky, he published in Vienna the work "Grammatik der Ruthenischen Sprache" ("Grammar of the Ruthenian [i. e. Ukrainian] Language", 1913).
In addition, together with Smal-Stotsky he wrote the textbook for secondary schools "Ruska Grammatika" ("Ruthenian [i. e. Ukrainian] Grammar", Chernivtsi, 1893), which had four editions and until 1928 served as a textbook on the Ukrainian language in secondary schools in Galicia and Bukovyna.
He participated in the drawing up of spelling in the Western Ukraine on the phonetic principle, as opposed to the existing etymological one.