The policy of Russification of Finland was a governmental policy of the Russian Empire aimed at limiting the special status of the Grand Duchy of Finland and possibly the termination of its political autonomy and cultural uniqueness in 1899–1905 and in 1908–1917, fully integrating Finland to the Russian Empire. It was a part of a larger policy of Russification pursued by late 19th–early 20th century Russian governments which tried to abolish cultural and administrative autonomy of non-Russian minorities within the empire.

The two Russification campaigns evoked widespread Finnish resistance, starting with petitions and escalating to strikes, passive resistance (including draft resistance) and eventually active resistance. Finnish opposition to Russification was one of the main factors that ultimately led to Finland's declaration of independence in 1917.

After Napoleon's victory over the Russian Empire in the June 1807 Battle of Friedland, tsar Alexander I was forced to sue for peace with the First French Empire in the Treaties of Tilsit (7 July 1807). Alexander agreed to join the Continental System against the British Empire, to launch the Anglo-Russian War (1807–1812), and to force Sweden (which maintained extensive trade relations with the British) to join the Continental System as well. Swedish king Gustav IV Adolf delayed his response to Alexander's ultimatum until he brokered an alliance with Britain in February 1808, after which he rejected Alexander's demands. In response, Imperial Russia invaded Swedish Finland in what later became known as the Finnish War (21 February 1808 – 17 September 1809), which ended favourably for Alexander.

In 1809, the lost territory of Sweden became the Grand Duchy of Finland, an autonomous part of the Russian Empire. The Diet of Porvoo (later the Diet of Finland) recognized Alexander I of Russia as grand duke on 29 March 1809. For his part, Alexander confirmed the rights of the Finns, in particular, promising freedom to pursue their customs and religion and to maintain their identity:

Providence having placed us in possession of the Grand Duchy of Finland, we have desired by the present act to confirm and ratify the religion and the fundamental laws of the land, as well as the privileges and rights which each class in the said Grand Duchy in particular, and all the inhabitants in general, be their position high or low, have hitherto enjoyed according to the constitution. We promise to maintain all these benefits and laws firm and unshaken in their full force.

This meant that the old Swedish instrument of government from 1772 and the Union and Security Act from 1789 continued to be used in regards to the Finnish form of government. It also meant that the Swedish Civil Code of 1734 continued as the fundamental law of Finland.^{[citation needed]}

This promise was maintained; indeed, Alexander II amplified the powers of the Finnish diet in 1869. Finland enjoyed prosperity and control over their own affairs, and remained loyal subjects for nearly a century.

The manifesto which Nicholas II issued on 15 February 1899 was cause for Finnish despair. The manifesto was forced through the Finnish senate by the deciding vote of the senate president, an appointee of the tsar—and after the Governor-General of Finland, Nikolay Bobrikov, had threatened a military invasion and siege. While ostensibly affirming the Finns' rights in purely local matters, the manifesto asserted the authority of the state in any and all matters which could be considered to "come within the scope of the general legislation of the empire".