1H-Phenalene, often called simply phenalene is a polycyclic aromatic hydrocarbon (PAH).

Like many PAHs, it is an atmospheric pollutant formed during the combustion of fossil fuels.

[2] It is the parent compound for the phosphorus-containing phosphaphenalenes.

The name was proposed by German chemists in 1922 as a contraction of periphenonaphthalene.

[3] Phenalene is deprotonated by potassium methoxide to give the phenalenyl anion.