In chemistry, delocalized electrons are electrons in a molecule that do not belong to a single atom or a covalent bond. Delocalized electrons are part of a pi electron system that extends over several adjacent atoms. Delocalized electrons can be found in Conjugated systems of double bonds and in aromatic systems.

In the simple aromatic ring benzene the delocalization of six pi electrons electrons over the whole ring is often indicated by the circle:

Alternatively, all possible mesomeric structures can be drawn inside square brackets separated by double arrows. This style should be used for polycyclic aromatic rings: