The cubic metre (in Commonwealth English and international spelling as used by the International Bureau of Weights and Measures) or cubic meter (in American English) is the unit of volume in the International System of Units (SI).

An alternative name, which allowed a different usage with metric prefixes, was the stère, still sometimes used for dry measure (for instance, in reference to wood).

A cubic metre of pure water at the temperature of maximum density (3.98 °C) and standard atmospheric pressure (101.325 kPa) has a mass of 1000 kg, or one tonne.

A cubic metre is sometimes abbreviated to m^3, M3, m**3, cum, m3, CBM, cbm when superscript characters or markup cannot be used (e.g. in some typewritten documents and postings in Usenet newsgroups).

The "cubic metre" symbol is encoded by Unicode at code point U+33A5 ㎥ SQUARE M CUBED.