In short, yes -- most any steel, under the right conditions and if truly neglected, can oxidize (rust).
What we call "stainless steel" is no exception.
Think of stainless steel as rust-resistant, not rust-proof. The advantage of a stainless-steel knife blade is that it requires less care, less often, but that doesn't mean it can be completely ignored without tempting the effects of oxidation.
Consider that your car's maintenance-free battery still needs maintenance. It's wise to check the pressure regularly in run-flat tires. And your knife's stainless-steel blade will benefit from being wiped clean and dry after it gets dirty or wet.