It comes from a language called Yiddish which was spoken by European Jews. It is a mixture of Hebrew, German and various Slavic languages. Prior to WWII about eleven million people spoke Yiddish; newspapers and books were published in the language, and there was Yiddish theater in Europe, the United States and Latin America. Oy! can mean any number of things, depending on the context and the way it is said. It can express both dejection and joy; ecstasy and horror. Oy Vay literally means oh pain, but it is often used to express just the opposite. A book entitled The Joys of Yiddish by Leo Rosten lists 29 ways the expression Oy! can be used. Example: They did what to the network? Oy vay!
OY VAY
Meaning of OY VAY in English
Slang English vocab. Английский сленговый словарь. 2012