He’s not a scientific genius like many of foes or his dad, and it does seem he’s often being played by supervillians. How smart is he?.
He’s as dumb as a lump of kryptonite. Come on, he thinks wearing a pair of specs makes him look different enough not to be recognised out of uniform!
Alas, the complexities of the DC Universe require this: Which Superman?
Come now, the “Can’t Recognize the Superhero in Civilian Guise” is far older a trope than the “Stormtrooper Effect!” 
If the DC Heroes RPG is any inidication, pretty damn smart. The game uses a system of “Attribute Points” (AP), wherein a 2 is considered “normal”, and every point increase is twice that of its predecessor. Thus, 3AP is twice as great as 2AP, 4AP is twice as great as 3AP, etc. For reference, then, a normal person would have stats of 2AP across the board - strength, intelligence, etc. Superman has a Strength of 25AP (meaning he’s 2[sup]25[/sup] as strong as a normal guy)…and an Intelligence of 11AP. For further reference, Batman has a 12AP intelligence.
Granted, I can’t say how “canon” the game is with respect to the actual comics, and I’d also suppose that a lot would depend on how the characters are written at any given time.
I think he’s dumb as a rock. It’s the only way an omnipotent superhero could not solve all of the world’s problems in an instant.
ETA: Finch, that was cute but incredibly geeky. 
Exactly.
Silver Age Superman was a genius. He explicitly possessed Super-Intelligence and built all manner of highly-advanced devices over the course of his life. Recall that even as Superboy, he had robots that were indistinguishable from human beings. Various looks into his Fortress of Solitude revealed other robots and computers that he invented. Recall also that it was a big deal that even he couldn’t think of a way to un-shrink Kandor.
In the Silver Age, this was true of all Kryptonians. When Superman observes Krypton’s past, he sees parents remarking - with worry - that their toddler had not yet mastered advanced calculus (or something like that).
Grant Morrison brought this aspect of Supes back in All-Star Superman.
Post-Crisis Superman was just a generally bright guy, but no scientific marvel.
Now, post-Infinite Crisis, Kurt Busiek gave Superman back some sort of super-intelligence, but, as far as I know, nobody has really touched on this and he more or less acts like a generally bright guy again.
The only constant when discussing Superman’s intelligence is that he turns into a moron whenever he’s in proximity to Batman, because otherwise Batman would be completely useless in Superman/Batman teamups.
Super-intelligent.
Seriously, for most of the Silver Age, and currently, that was quite seriously one of his powers. Back in the Silver Age it was…applied inconsistently - he’d make some really bizarre leaps of logic. Since it’s been reintroduced, it’s been presented as an improved ability to process and retain information.
Even when it wasn’t, he was fairly bright. Hanging around with people like Batman, and having enemies like Luthor and Brainiac, he doesn’t seem terribly impressive in comparison, but he’s always been on the ball.
Jesus, Mary, and Joseph, ain’t that the truth.
“Clark, those robots you’ve been using that have, in fact, even fooled me in the past?”
“Daaaaaaaaaaaaaaaah … uh-huh?”
“Pollution is causing them to break down. You’ll have to stop using them.”
“Daaaaaaaaaaaaaaaah … okaaaaaaay, Bruce.”
“Sucker.”
Okay, if his glasses are a gadget that alters peoples perception of him, I’ll change my mind and say he’s Super-Smart.
Superman #330 (Dec 1978).
During the Cary Bates era, his “Super intelligence” seemed to consist mostly of being able to work out math problems as fast or faster than advanced Earth computers, and building the aforementioned androids, but he could be surprisingly dumb when the story required it, getting stymied by the Toyman and the like.
I’m not really up on the Superman mythos, but the way he tricked General Zod and his cronies out of their powers in Superman II seemed pretty clever to me.
In the Lois and Clark episode (Yes, I know, the series only followed comic book canon loosely) Through a Glass Darkly, Superman had to pass some sort of Kryptonian intelligence test by building a kind of CD player from scratch in order to play a message from the surviving Kryptonians who were seeking out Kal-El for their leader. That suggests a higher than human intelligence.
I think it’s also that partly he just doesn’t think sneaky. That’s why bad guys get the drop so often: he can’t understand their minds.
Since the Silver Age was my era, I feel compelled to chime in.
Sure, Supes was a scientific genius. He could pretty much build anything and do complex mathematical calculations. But he never seemed that clever to me. The height of his street smarts was figuring out how to get Mr. Mxyzptlk to say his name backwards.
Even back then, I thought Batman was better at deduction.
[Andre the Giant/Fezzig]
"I just want you to feel that you are doing well!
[/atg/f]
Not very.
E.T.A. Full article is here I-Mockery.com - Tales from the Longbox! (and hilarious). I-mockery reviews Frank Miller’s Batman and Robin All Star. Beverage splattered monitor will ensue…
Ah, yes, the title whose most recent issue had to be recalled because the blacked-out swear words could still be seen faintly under the blacking-out. And whose second issue featured one of the most parodied lines of recent comic vintage: “Are you dense or retarded or something? Who the hell do you think I am? I’m the goddamn Batman!”
Please note–while Superman is smart, he is not devious.
Deceit is not his strong point. He solves problems straightforwardly.