None that would openly admit it.
But we likely have already.

I would be willing to bet we've had several already. Like others have said, it will be a while before we have an out atheist as president.

It already does. 45 said he's an atheist in "The Art of the Deal".
He's only pandering to the believers because he already knows how gullible
they are. He knows they'll believe anything, so he said he's a "christian".
As far as an open-atheist, no telling.

Probability is we have had at least a few.

We will be lucky if we ever have another president!

I'm sure we already have. They just couldn't come out.

I want a good president, not interested in the denomination,
just a good president.

Here's to hoping! And yes, I do believe it will happen. I read a few studies recently that in the last 10 years, people who are members of organized dropped 10% from 55% to 45% of the populous. That's a trend I like to see.

i don't think obama actually believes all that rubbish

its possible maybe i'll run

I think it would be a good thing for this country. The reality of it seems a bit dim which is unfortunate.

Sure, but it will require a few generations to die off first. Like anyone born between 1900 and 1990.

We already have!! Most just do not know, nor was it announced but hidden by charades.

Someday, but probably not in our collective lifetimes. In fact, I'd say it's likely that some other entity rather than the USA will be around at that time, due to economic and social pressures. (I'm talking the next 75-100 years from now.) The US is gradually becoming too large to govern as it is, and the pressures of an increasingly hostile environment on Earth (leading to mass migrations of climate refugees like you see Africa to Europe) and increasing disparity between the educated and non-educated will probably lead to the breakup of the US into smaller countries that encompass different regions. With that in mind, I would expect the western and eastern coasts above what used to be the Mason-Dixon line led by secular leaders (no doubt some of the atheist/agnostic), while the "Bible belt" and other more rural regions become increasingly more theocratic, perhaps even moving to a government by religious leaders, like we see in many current countries. It's a pattern that we've seen throughout history, with poorer, less educated citizenry opting for religion as their organizing force, while the more affluent and educated they get (see Northern Europe and Scandinavia), the more secular they become.

Openly atheist? No. I cannot imagine that.
I never imagined the USA was so religious until I joined this site.
From what I have read, many busiensses and workplaces sound more like sunday schools.

Yes.

I Do Not Care. Never been a fan of questioning strangers either.

"Ever" is a long time, but don't hold your breath.

An admitted one, but we have one now in my opinion...but undoubtedly others over the years have claimed to be christian, and went to church now and the...

Not likely, but then again I never thought that idiot Trump would ever be president...so you never know

In my opinion, it wouldn't matter one way or another. This country is ruled by the wealthy and powerful and nothing is going to change that will amount to anything.

An "Out" Atheist? I think we're a long, LONG way from that. There is still such a widely held view that if you don't have religion you cannot have morality.