Hello. I have been looking to locate my father who lived in the U.S. But now lives in Greece, I believe Thessaloniki. I have googled, tried the greecian net and even Facebook. I know his year of birth but can't make any progress. Can someone please help?

Usually your best bet is to try people who also knew or know him still. One of them knows someone who knows someone...
And actually Facebook is a pretty good place to start.
You could also sign up for Genie and Ancestry.com, in case other relatives are there too.
That city in Greece is pretty big. I found someone in a small town once just by going to the town post office and asking where they lived. (Of course that was many years ago.)

Thank you so much. I may try one person he was/is friends with providing I can locate him. I appreciate your help.

Hi, I'm Greek and the first and simplest way that comes in my mind in order to locate someone in Greece is OTE white pages. Have you tried that?

Thank you for your response. I actually tried that and wasn't able to get any info. I have however been in touch with the U.S. Embassy in Athens you suggest that I speak with an attorney who specializes in this sort of thing and who speaks English also. Sounds expensive but I believe it may be worth it. I now have what I believe is a valid address so, I'm getting closer.

Thanks again for your help with this.