Probably the first documented use of a number zero in the Old World was by Claudius Ptolemy in the Almagest (ca. 130 AD), although in the Americas the concept and symbol for zero existed much earlier.
Ptolemy employed the symbol ο̄ (“Hellenistic zero” ) within a Babylonian sexagesimal numeral system. The oldest known mention of zero and the decimal positional system are found in the Jainist cosmological text Lokavibhāga (AD 458). By the 11th century, the Hindu–Arabic numeral system, complete with zero, reached Europe.
In my handwriting, I almost always write this digit as a slashed zero, 0.