Smart and Stupid are direct opposites, so I would have to say, on the official question itself, No.
But as to the larger issue, one can easily be FOOLISH - someone who may be very intelligent, but makes poor decisions. My uncle is a great example... very factually knowledgeable, but made very poor decisions about sex, family, credit, and crime and it's pretty much ruined his life.
One can easily be IMMATURE - someone who may be very intelligent, but may conduct themselves in an improper manner, or be socially inept.
One can also easily be INARTICULATE, but be very intelligent. This OFTEN occurs with computer-oriented persons. They may be very brilliant programmers, but highly unable to communicate their ideas to others, especically those unfamilliar with technology.
Often people mistake other attributes, such as those above, for someone being "stupid". Personally, I believe much of it is due to their own laziness to properly look at the behavior and identify the true aspect they have a problem with. Instead, they take the easy way out, lump it all together, and brush someone off as being "stupid".