Can we say "an Olympics", "an/one Olympic Gam

Can we say "an Olympics", "an/one Olympic Games"?

No, it's usually plural. An Olympic game refers to one event in the Games.

I have seen some people use "Olympics" as a singular noun to refer to the Olympic Games of a certain year, but a cursory look at Google results shows that "Olympics" is usually treated as a plural. So you would say, "these Olympics", "those Olympics", "the Olympics are".

An "Olympic event" is often used when referring to a specific type of "game".

"Sailing is an Olympic event."

Yes, you actually can use "Olympics" as a singular; people do it all the time. "Has anyone ever seen an Olympics like this..." etc., etc. Yes, it's awkward, and people will very self-consciously alter it to "the Olympic games" to try to make it sound "right", but I think most of us think of it now as a single entity with a slightly ungainly name, and often refer to it grammatically as such. When we're not referring to it as a plural. It's almost like the term is in flux right now, and can occasionally go both ways.

I see many people use it singularly as a single Olympic Games.