Are many Americans living in Marbella, Spain?

It looks like I'll be moving there and was wondering what it is like to live there. Are there many Americans there? Is there some sort of ex-pats group? Is it nice? Is there much to do other than play golf and go to the beach? ...

There are lots of things to do...
But more than ex-pats american, you will find a huge amount of ex-pat brits.
I married a spaniard, and have lived here for nearly 36 years! My husband works in Marbella, but we actually live in Mijas-Costa (A bit less expensive area).
There is an American Club with several chapters along the Costa del Sol...One is in Marbella.
You can look it up
www.americanclubcostadel sol.com
There is a Consular Agency in Fuengirola, about 30 kms. east of Marbella. Their phone number is: 34 - 952 478 891
Your best bet on information would probably be the American Club..
The Costa del Sol is a lovely place to live...We have great weather most of the year, a wide variety of sports from tennis clubs to golfcourses, etc.
Cuisine from most nations all over the world. And also people! I think you will enjoy it here!
:-)

Why would you be concerned about ex-pats? Go and mingle with the real people. You will love it and them. I guarantee it. Just become as Spanish as you can. (of course, it's a massive tourist community, so...you have to get away from all that to meet the real Spain.)

Sue is right, go and mix with the local people. I have done exactly that. I'm British but I do my best to integrate into my local community. The Spanish people are wonderful, they will appreciate you learning the language and being part of their community. I've lived in Marbella (Nueva Andalucia) and Mijas Costa but now live near Nerja. I can't think of any Americans I've known living here though there will be a few. There are of course many British people. I do understand why you want ex-pats around you, but try and find an area where there is a mix of British & Spanish.

You are so lucky! Marbella is the one place in the world that I've been that has really impressed me.
I found that it was international, with lots of Europeans from all over, as well as some Aussies, a few Africans and everyone else. They were all friendly and nice, and so were the locals.
If I ever get the chance, I will live there myself!

I don't know about activities other than shopping, eating, partying, beaching, gambling and playing golf, cuz that's all we did when we stayed.
I'm sure there's other stuff to do there, though.