He graduated from the University of Graz as a doctor of philosophy, and was for a time professor of philosophy there. In 1838 he went to the University of Vienna, where he received the degree of doctor of law. During his studies, he became influenced by the works of the Slovenian philologist and linguist Jernej Kopitar. He abandoned law, devoting most of his later life to the study of Slavic languages.
In 1844, he obtained a post at the Imperial Library of Vienna, where he remained to 1862. In 1844, he published a review of Franz Bopp's book Comparative Grammar, which attracted attention from the Viennese academic circles. This publication then launched a long series of works, in which Miklošič showed an immense erudition. His works led to a revolutiony change in the study of Slavic languages.
In 1849 Miklošič was appointed to the newly created chair of Slavic philology at the University of Vienna, and he occupied it until 1886. He became a member of the Academy of Vienna, which appointed him secretary of its historical and philosophical section, a member of the council of public instruction and of the upper house, and correspondent of the French Academy of Inscription. His numerous writings deal not only with the Slavic languages, but with Romanian, Albanian, Greek, and the language of the Roma and Sinti peoples.
In the Spring of Nations of 1848, Miklošič, who was 35 at the time, actively engaged in the Slovenian national movement. He was the chairman of the political assotiation, called Slovenija (Slovenia) organized by Slovenian students that studied in Graz and Vienna. Next to Matija Majar, he was among the authors who elaborated the political demand for a United Slovenia. After the failure of the revolutionary requests, he again turned to an exlusively academic activity.
Walter Lukan (Hg.): Franz Miklosich (Miklošič): neue Studien und Materialien anläßlich seines 100. Todestages. Wien 1991 (= Österreichische Osthefte: Sonderheft 33).
Katja Sturm-Schnabl, Der Briefwechsel Franz Miklosich's mit den Südslaven = Korespondenca Frana Miklošiča z Južnimi Slovani, Obzorja, Maribor 1991, XXIV, 855 S., ISBN 86-377-0565-0.
Katja Sturm-Schnabl, Franz Miklosich als Wegbegleiter bei der Entstehung der ukrainischen Schriftsprache. In: Juliane Besters-Dilger, Michael Moser, Stefan Simonek (Hg.), Sprache und Literatur der Ukraine zwischen Ost und West – Мова та література України між сходом і заходом. Bern; Berlin; Bruxelles; Frankfurt am Main; New York; Oxford; Wien: Lang 2000,195 – 209.
Katja Sturm-Schnabl, Franz Miklosich – ein „Europäer“ im 19. Jahrhundert. Short version http://www.inst.at/studies/s_0104_d.htm
Katja Sturm-Schnabl, Fran Miklošič, An Early Visionary of European Integration in Philological Studies. The Difficult Path Towards the Acceptance of the Concept of Diversity and Plurality. http://cf.hum.uva.nl/natlearn/
Katja Sturm-Schnabl, Aktualnost Miklošičevega znanstvenega dela in misli. In: Jezikovni zapiski . Glasilo inštituta zs slovenski jezik Frana Ramovša ZRC SAZU 10/2(2004)19 – 46.