Yes, if you count really tiny city-states like the above mentioned Vatican City and San Marino. Here’s a wiki list.
Aside from those, everywhere - even war torn countries like Syria - have commercial airports. You might need to make multiple connecting flights to find an airline which actually goes there, but someone will, at some point in time, unless the airport is actively under siege.
It amazes me sometimes how commercial travel seems to be able to avoid political skirmishes. When I was looking for a country to visit for a beach holiday after a week in Israel, I was amazed by the ease and frequency of low cost flights to Turkey. Turns out Turkey is very popular with Israeli holiday makers, who knew?