Vyacheslav, also transliterated Viacheslav or Viatcheslav (Russian: Вячеслав, romanized: Vyacheslav [vʲɪtɕɪˈslaf]; Ukrainian: В'ячеслав, romanized: Viacheslav [u̯jɐtʃeˈslɑu̯]), is a Russian and Ukrainian masculine given name. It is the equivalent of Belarusian Вячаслаў/Вацлаў (transliterated Viačaslaŭ/Vaclaŭ, or Viachaslau/Vaclau), Croatian Vjenceslav, Czech Václav, Polish Wacław and Więcesław — Latinised as Wenceslaus. Also: Romanian of Moldova Veaceslav.
It is a Slavic dithematic name (that is, composed of two lexemes) derived from the Slavic words vyache, "great(er)", and slava, "glory, fame". Common short forms are Slava, Slavik.
Feminine forms: Vyacheslava, Więcesława.