Correlation between resonance and coordinate covalent bond So I was listening to an online chemistry lecture the other day, and the theme was "bond".

In the 'coordinate covalent bond' part, the teacher said "Examples of the coordinate covalent bond can be $\ce{SO_2}$, $\ce{HNO_3}$, etc." and I could figure out that both molecules have resonance structures: between $\ce{N}$ and $\ce{O}$ atoms in $\ce{HNO_3}$, between $\ce{O}$ and $\ce{S}$ atoms in $\ce{SO_2}$. Also I am aware of the resonance structures in the $\ce{C_6H_6}$(benzene) molecule, so I looked up the Wikipedia page and could find this sentence:

"..., while the VB description involves a superposition of resonance structures."

So I became curious about this: Is there any close correlation between resonance and coordinate covalent bond? In other words, is it safe to view a molecule as having coordinate covalent bond when it has resonance structure in it?
Based on the examples you have given, that does appear to be the case but if you look for more examples you'll find that this is not particularly true. Two well known compounds can be used to demonstrate:

(1) Carbon Monoxide: Coordinate Covalent Bond from O -> C, but no resonance structure

(2) Benzene: Resonance Structure but no Coordinate Covalent Bonds