Borates are the name for a large number of boron-containing oxyanions. The term "borates" may also refer to tetrahedral boron anions, or more loosely to chemical compounds which contain borate anions of either description. Larger borates are composed of trigonal planar BO₃ or tetrahedral BO₄ structural units, joined together via shared oxygen atoms and may be cyclic or linear in structure. Boron most often occurs in nature as borates, such as borate minerals and borosilicates.

The borate minerals are minerals which contain a borate anion group. The borate (BO₃) units may be polymerised similar to the SiO₄ unit of the silicate mineral class. This results in B₂O₅, B₃O₆, B₂O₄ anions as well as more complex structures which include hydroxide or halogen anions. The [B(O,OH)₄]^- anion exists too.