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