Titular nation (титульная нация) was a term introduced in the Soviet Union to denote nations that give rise to titles of autonomous entities within the union: Soviet republics, autonomous republics, autonomous regions, etc.

For an ethnos to become titular nation, it had to satisfy certain criteria in terms of the amount of population and compactness of its settlement. The language of a titular nation was declared an additional (after Russian) official language of the corresponding administrative unit.

The notion worked well for the cases of well established, homogeneous and relatively developed nations.

In a number of cases, in certain highly multiethnic regions, such as Caucasus, the notion of titular nation introduced intrinsic inequality betwen titular and non-titular nations, especially since the introduction of the "korenizatsiya" politics, according to which representatives of a titular nation were promoted to management position.

In other cases, such as in Kazakhstan this notion failed to take into an account tribal differences within an ethnos, formally considered a single nation.