Ukase (Russian: указ, ukaz) in Imperial Russia was a proclamation of the tsar government, or a religions leader patriarch that had the force of law. An example is the "Ems ukase" forbidding the public use of Ukrainian. Adequate translations are "edict" or "decree". Compare fiat and fatwa.

After the Russian Revolution, a government proclamation of wide meaning was called a "decree" (Russian: декрет, dekret); more specific proclamations are called ukase (указ). Both terms are usually translated as 'decree'.

According to the Russian Federation's 1993 constitution, a ukase is a Presidential decree. Such ukases have the power of laws, but may not alter the regulations of existing laws, and may be superseded by laws passed by the State Duma.