A Military Unit Number (Russian: войсковая часть, в/ ч; Ukrainian: військова частина, в/ ч) is a unique numeric code assigned to military units of the Soviet Union and some Post-Soviet states. It is usually a four or five digit code for the purpose of identifying units of the armed forces and internal troops.

Military Unit Numbers for ground forces are assigned for a specific military unit (corps, division, brigade, etc.) while for the navy it is assigned to an individual ship. The number is also used for the unit's military mail and other logistics.