oxonium

Oxonium may refer to:

Oxonium ion, any ion which contains a tricoordinated oxygen atom, {{chem2|RR'R"O+}}
Oxonium, an IUPAC name for the simplest oxonium ion, hydronium, {{chem2|H3O+}}
Oxonium (often abbreviated to Oxon.), sometimes used in university circles as a Latin name for Oxford University in England