The 6 January Dictatorship was a royal dictatorship established in the Kingdom of Serbs, Croats and Slovenes by King Alexander I with the ultimate goal to create a Yugoslav ideology and a single Yugoslav nation. It began on 6 January 1929, when the king prorogued parliament and assumed control of the state, and ended with the 1931 Yugoslav Constitution.

Alexander I, also known as Alexander the Unifier, was King of the Serbs, Croats and Slovenes from 16 August 1921 to 3 October 1929 and King of Yugoslavia from 3 October 1929 until his assassination in 1934. His reign of 13 years is the longest of the three monarchs of the Kingdom of Yugoslavia.