Sviatoslav (Russian: Святосла́в, romanized: Svjatosláv, IPA: [sʲvʲɪtɐˈslaf]; Ukrainian: Святосла́в, romanized: Svjatosláv, IPA: [sʲw(j)ɐtoˈslɑu̯]) is a Russian and Ukrainian given name of Slavic origin.
Cognates include Svetoslav, Svatoslav, Świętosław, Svetislav.
It has a Pre-Christian pagan character and means "one who worships the light" (likely in reference to the sun).
In Christian times the name's meaning started to be associated with the Proto-Slavic roots *svętъ (holy, light, world) and *slava (glory), to be explained as "One who worships the Holy".
A diminutive form for Sviatoslav is Svetlyo (Bulgarian), Slava (Russian), Świętek (Polish), Slavko, Sveto, Svet, Sviat, Sviatko (Ukrainian).