Klaus Werner Iohannis (Romanian pronunciation: [ˈkla.us joˈhanis], German: [ˈklaʊ̯s joˈhanɪs]; also spelled Johannis; born 13 June 1959) is the current President of Romania. He became leader of the National Liberal Party in 2014, after having served as leader of the Democratic Forum of Germans in Romania from 2002 to 2013. Iohannis was a physics teacher and a school inspector before entering full-time politics.

Iohannis was first elected mayor of the city of Sibiu in 2000, representing the Democratic Forum of Germans in Romania. Although the German population of the once predominantly German-speaking city of Sibiu has declined to a tiny minority, Iohannis won a surprise victory and was re-elected by landslides in 2004, 2008 and 2012. Iohannis is credited with turning his city into one of Romania's most popular tourist destinations, and the city was declared the European Capital of Culture in 2007. In February 2013, Iohannis became a member of the National Liberal Party, accepting an invitation from Liberal leader Crin Antonescu, and was immediately elected the party's First Vice President, becoming the party's President the following year.

In October 2009, four of the five political groups in the Parliament, excluding the Democrat Liberal Party of then-President Traian Băsescu, proposed him as a candidate for the office of Prime Minister of Romania; however, Băsescu refused to nominate him despite the Parliament's adoption of a declaration supporting his candidacy. He was again the candidate for Prime Minister of the National Liberal Party and the Social Democratic Party in the elections in the same year.

Iohannis is the first Romanian president to come from an ethnic minority. He is a Transylvanian Saxon, part of Romania's German minority which settled in Transylvania in the 12th century.