Olha is Ukrainian version of
Olga, which is female name popular in Eastern Europe and Latin America. Name originates from Scandinavian "
Helga". To
Kievan Russ (Ukraine now) was brought with invited Scandinavian
Princes around 500-600 AD. But became popular around introduction of Christianity around 900 AD. Well-known is Princess Olga, grandmother of Prince
Volodymyr the Great (the one who made Christianity Official State Religion). She was the first Christian Princess in Kievan Russ, big fan of books and education. I believe, she was the single cause of popularity of the name in Slavic countries. Not many people new she wasn't from noble family, but a daughter of ferryman. She driving paddle ferry across the Dnipro River and that is there Prince Igor spotted her. She had many sons. After her husband was killed during tax ride, she
sorely ruled country until her oldest son reached adolescence and was closely supervising state offers until very old age.
Stereotypically, attributes of this great princess are applied to all
Olgas. Name is particularly popular among Ukrainian
Diaspora. There is no difference in how
Ukrainians or Russians pronounce the name in their native language, but there is difference is how they spell their names in English. You can see the origin by differed spelling - Olha (Ukraine), Olga (Russian speaking countries, Poland, Latin America).
For short -
Olia, Olichka, Olyunia, Olka,
Olana.
There are also male name Olga in use in Turkey
