103

103 may refer to:
 * 103 (number), the number
 * AD 103, a year in the 2nd century AD
 * 103 BC, a year in the 2nd century BC
 * 103 (Tyne Electrical Engineers) Field Squadron, a territorial regiment
 * 103 (Newcastle) Field Squadron, Royal Engineers
 * 103 (Lancashire Artillery Volunteers) Regiment Royal Artillery
 * 103 series Japanese rolling stock
 * 103, a development name for the Tupolev Tu-2
 * 103 Hera, a main-belt asteroid