Olga is a female name of Slavic origins. It is the equivalent of Helga, and derived from the Old Norse adjective heilagr (prosperous, successful). The name was brought to Russia in the 9th century, by the Scandinavian settlers who founded Kievan Rus'.
It is used in Russia (Ольга), Ukraine (Ольга, transliterated Olha), Belarus (Вольга, transliterated Vol'ha), Bulgaria (Олга transliterated Ólga), the Czech Republic, Greece and Cyprus (Όλγα, Ólgha), Georgia (ოლგა (Olga) or more archaic ოლღა (Olgha)), Latvia, Lithuania (Alge, Algis), Finland, Poland, Hungary, Romania, the Balkans (Serbian Олга or Оља), Western Europe and Latin America (Olga). It is also much in use in Scandinavia.
Name days (St. Olga of Kiev): Bulgaria, Poland, Czech Republic, Greece and France – July 11, Slovakia – July 23, Ukraine, Russia – July 24, Hungary – July 27.
The male form is Oleg (Олeг).