The selenite anion is a selenium oxoanion with the chemical formula SeO32−.
A selenite (compound) is a compound that contains this ion.
In slightly acid conditions, the hydrogenselenite ion, HSeO3−, is formed; in more acidic conditions selenous acid, H2SeO3, exists.
Most selenite salts can be formed by heating the relevant metal oxide with selenium dioxide, e.g.:
See Category:Selenites for a list.