NM may stand for:

• Air Madrid and Mount Cook Airline IATA airline designator
• Neurofiber Mitosis, a nerve disease, sometimes confused with Neurofibromatosis
• nm (Unix), a computer program used as an aid for debugging
• Nautical mile (nm)
• New Mexico (NM)
• Newton metre (N m or N·m), a unit of moment
• Nanometre (nm, 10^-9 m), a thousand-millionth of a metre
• "Not much" (nm), in Internet slang
• "Never mind" (nm), in Internet slang
• Non-metallic power cable, widely used in electrical house wiring
• Northwestern Mutual, a life insurance and financial services company based in Milwaukee, WI
• Network Module.

The similar acronym Nm³ stands for normal cubic metres, a unit of volume, not Newton cubic metres. Normal in this context means at standard temperature and pressure.