Kniaz, knyaz or knez is a Slavic title found in most Slavic languages, denoting a royal nobility rank. It is usually translated into English either as Prince or less commonly as Duke. In the Vatican, some Croatian knezes, such as Stjepan Držislav, were referred to as "Dux Croatorum" or "Dux Chroatorum".

Today the term knez is still used as the most common translation of "prince" in Croatian and Serbian literature. Another translation is kraljević (Slovene: kraljevič) meaning "little king" or "kingly", such as Kraljević Marko, though this term is used to refer to a prince or princess of royal birth, son or daughter of a king. Knez is nowadays a very common surname in some ex-Yugoslavian countries, mostly in Croatia, Montenegro and Serbia, but also among immigrants in Slovenia.

The female form transliterated from Bulgarian and Russian is knyaginya (княгиня), kniahynia (княгиня) in Ukrainian, kneginja in Slovene, Croatian and Serbian (Serbian Cyrillic: кнегиња). In Russian, the daughter of a knyaz is knyazhna (княжна), in Ukrainian is kniazivna (князівна). In Russian, the son of a knyaz is knyazhich (княжич) (old form).

Velikite Balgari (Bulgarian: „Великите българи“, The Great Bulgarians) was the Bulgarian spin-off of the 2002 Greatest Britons program produced by the BBC. Aired on the Bulgarian National Television's Kanal 1, its first stage began on 9 June 2006 and finished on 10 December, with a show on 23 December announcing the names of the Top 100 as chosen by popular vote. The Top 10 were announced in alphabetical order. In the second stage, which lasted until 17 February 2007, the viewers determined the order in the Top 10. Documentaries dedicated to every Top 10 personality were aired during the second stage.