Pyridazine is a heterocyclic organic compound with the molecular formula (CH)₄N₂. It contains a six-membered ring with two adjacent nitrogen atoms, and is aromatic. It is a colorless liquid with a boiling point of 208 °C. It is isomeric with two other (CH)₄N₂ rings, pyrimidine and pyrazine.

Pyridazine is a heterocyclic organic compound with the molecular formula (CH)₄N₂. It contains a six-membered ring with two adjacent nitrogen atoms, and is aromatic. It is a colorless liquid with a boiling point of 208 °C. It is isomeric with two other (CH)₄N₂ rings, pyrimidine and pyrazine.