Dimethylhydrazine is the name of two compounds with the molecular formula C2H8N2. These are:
- unsymmetrical dimethylhydrazine (1,1-dimethylhydrazine), with both methyl groups bonded to the same nitrogen atom
- symmetrical dimethylhydrazine (1,2-dimethylhydrazine), with one methyl group bonded to each of the two nitrogen atoms