The written form corresponds to two names that are different and unrelated in origin.
The first is the Greek name Ἴων (Iōn), after the mythical founder of the Ionians; the modern (demotic) Greek equivalent is Ionas.
Common diminutives are Ionel and Ionuț.
The "Ion" spelling is also used as a male forename in the Basque language, again as a cognate of "John" and sometimes used interchangeably with "Jon".
Notable people given name Ion include: