603 (disambiguation)

603 may refer to:

• 603 (number), the natural number following 602 and preceding 604
• A year: 603 CE or 603 BCE
• The North American telephone area code 603
• The US state of New Hampshire, which solely uses the 603 area code.
• The IBM 603 Electronic Multiplier
• The PowerPC 603 microprocessor
• The socket 603 motherboard socket for the Intel Xeon microprocessor
• Minor planet 603, named Timandra
• The Tatra 603 automobile
• The Bristol 603 automobile
• The Daimler-Benz DB 603 aircraft engine
• The Mercedes-Benz OM603 diesel engine
• The large number 10⁶⁰³, known as ducentillion (USA and modern British) or thousand centillion (traditional British) or centilliard (traditional European)