Archeologist, art historian, professor and member of the Hungarian Academy of Sciences. He joined the Benedictine order and became Doctor of Philosophy. He taught Hungarian language and literature and Latin at the secondary school in Győr from 1839, and later natural history. From 1842 onwards he was in charge of teaching natural sciences to students at the Benedictine school of philosophy in Győr. From 1845 onwards he taught natural history. During the war of independence of 1848-49 he obtained the rank of a captain. He was sentenced to imprisonment for 8 years during the Bach era.

He was released from prison in 1854 and worked as a teacher again. He moved to Pest in 1861, left the Benedictine order and worked in the archives of manuscripts at the Hungarian Academy of Sciences, then was appointed a director of a secondary school in 1862 and became a teacher of archeology at the university. He was elected to be in charge of the archeological collection at the Hungarian National Museum. In 1877 he became the canon of Nagyvárad. Rómer was one of the founders and representatives of Hungarian archeology and a co-founder of the Hungarian Society of History.