I want to know if anyone can help me.

I'm South African born. My parents were not married and my father is not on my birth certificate. My fathers father was born in Greece and held a Greek passport, but has reciently died. Can I and if I can, how do I apply for Greek citizenship as I want to work in Europe.

Per Greek law, if your parents were not married at the time of your birth, then your father has to formally "recognize" you as his legitimate child for you to get the benefit of Greek citizenship.

Since he has died, either of his two parents [your grandparents] may also perform the recognition. So hopefully one of your two grandparents is still alive and can perform this task.

Otherwise, you are out of luck, and need to go through the normal naturalization process.