Hexaborane(12) is an inorganic compound with the formula B<sub>6</sub>H<sub>12</sub>. It is an obscure member of the boranes. It is a colorless liquid that, like some other boron hydride clusters, is readily hydrolyzed and flammable.
The molecular structure conforms to C<sub>2</sub> symmetry group. With the formula B<sub>n</sub>H<sub>n+6</sub>, it is classified as an arachno-cluster. As such the boron positions match six of the boron positions in the closo-B<sub>8</sub>H.
It is typically prepared by the cluster expansion method from B<sub>5</sub>H, the conjugate base of pentaborane(9):