Dinitrobenzenes are nitrobenzenes composed of a benzene ring and two nitro group (-NO<sub>2</sub>) substituents. The three possible arrangements of the nitro groups afford three isomers, 1,2-dinitrobenzene, 1,3-dinitrobenzene, and 1,4-dinitrobenzene. Each isomer has the chemical formula C<sub>6</sub>H<sub>4</sub>N<sub>2</sub>O<sub>4</sub> and a molar mass of about 168.11 g/mol. 1,3-Dinitrobenzene is the most common isomer. It is used as a precursor to 1,3-diaminobenzene and 3-nitroaniline.
The dinitrobenzenes are all crystalline solids. The boiling points of the three isomers are relatively close; however, the melting points significantly differ. 1,4-Dinitrobenzene, which has the highest symmetry, has the highest melting point.