The 1527 election in Cetin (Croatian: Cetinski sabor, meaning Parliament on Cetin or Parliament of Cetin) was an assembly of the Croatian Parliament in the Cetin Castle that followed a succession crisis in the Kingdom of Hungary caused by the death of Louis II, and which resulted in the Kingdom of Croatia joining the Habsburg Monarchy. The charter electing the Habsburg Archduke of Austria Ferdinand I as King of Croatia was confirmed with the seals of six Croatian nobles and four representatives of the Archduke.
Faced with the overwhelming force of the Ottoman Empire, the nobility of the Kingdom of Croatia was alarmed as the Siege of Belgrade of 1521 caused the Kingdom of Hungary to lose its last fortress on the Danube to Suleiman the Magnificent. King Louis II showed no interest in defense, and was in a dire financial situation at the time. The Croatians appealed to the Pope, Venice, Emperor Charles V and Archduke Ferdinand for help, but had little success.
The majority of Croatian magnates and members of lower nobility were keen to elect a new king. The gathering (sabor) was caused by a monarchical crisis after the death of king Louis and a major defeat of the Kingdom of Hungary at the Battle of Mohács on 29 August 1526. Louis II had held the crown of Croatia among other titles, but left no heir.