After graduating from the Faculty of Physics of the Babeș-Bolyai University (UBB) in Cluj-Napoca in 1983, Iohannis worked as a high school physics teacher at various schools and colleges in his native Sibiu, including, from 1989 to 1997, at the Samuel von Brukenthal National College, the oldest German-speaking school in Romania. From 1997 to 1999, he was Deputy General School Inspector of Sibiu County, and from 1999 until his election as mayor in 2000, he was the General School Inspector, head of public schools in the county.