Nobleite is a rare borate mineral with the chemical formula CaB<sub>6</sub>O<sub>9</sub>(OH)<sub>2</sub>÷3H<sub>2</sub>O. It was discovered in 1961, in Death Valley, California, and is named for Levi F. Noble, a USGS geologist, in honor of his contributions to the geology of the Death Valley region.
Nobleite has also been identified at two localities in Chile and Argentina.