Cyclopropenone is an organic compound with molecular formula C3H2O consisting of a cyclopropene carbon framework with a ketone functional group.

It is a colorless, volatile liquid that boils near room temperature.

[1] Neat cyclopropenone polymerizes upon standing at room temperature,[2] and chemical vendors typically supply it as an acetal.

[3] The chemical properties of the compound are dominated by the strong polarization of the carbonyl group, which gives a partial positive charge with aromatic stabilization on the ring and a partial negative charge on oxygen.

It is an aromatic compound.