Grand Duke of Finland (Finnish: Suomen suuriruhtinas, Swedish: Storfurste av Finland) was a title in use, sometimes sporadically, between 1584 and 1808. 1809-1917 it was the official title of the head of the autonomous Grand Duchy of Finland.

In 1584, King John III of Sweden, who had previously been Duke of Finland, began using the subsidiary title Grand Duke of Finland (in Swedish Storfurste till Finland). This is to be seen as a marking of the Swedish sovereign's power in Finland, as well as the import of Finland as a part of the Sweden Proper. It did not result in any increase of Finnish independence.

During the next two centuries, the title was used by some of John's successors on the throne, but not all (e.g. his brother Charles IX used King of the Finns in stead). Usually it was just a subsidiary title of the King, and so it was used only at very formal occasions. However, in 1802, King Gustav IV Adolf gave the title to his new-born son, Prince Carl Gustaf, who died three years later.

During the Finnish War, the four Estates of occupied Finland were assembled at the Diet of Porvoo on March 29, 1809 to pledge allegiance to Alexander I of Russia. Following the Swedish defeat in the war and the signing of the Treaty of Fredrikshamn on September 17, 1809, Finland became a true grand duchy tied to the Russian Empire by means of personal union. The Tsar ruled the country, which nevertheless enjoyed a degree of autonomy, as Grand Duke of Finland until its independence in 1917. Then the new elected monarch (Väinö I) was to be king in stead, marking the new status of the nation, but he never reigned until republic was proclaimed.

See also

• Governor-General of Finland
• List of Finnish rulers
• History of Finland
• Dukes of Swedish Provinces
• Anjala conspiracy