The Governorate of Nyland-Tavastehus (Нюланд-Тавастгусская губерния, Nylands och Tavastehus län, Uudenmaan ja Hämeen lääni) was a governorate of the Grand Duchy of Finland, in the Russian Empire, from 1809 to 1831. In 1831 it was divided into the Governorate of Nyland and the Governorate of Tavastehus.
The ceded territories became a part of the Russian Empire and was reconstituted into the Grand Duchy of Finland, with the Russian Tsar as Grand Duke. The Governorate of Nyland-Tavastehus was established in 1809 from the County of Nyland and Tavastehus, which had been the administrative division as a part of Sweden. Åbo (Або, Turku) was the largest city in Finland had served as a capital, while it was a part of Sweden, but that role would now be given to Helsingfors (Helsinki, Гельсингфорс) and successively the main institutions of government were moved there. After the big fire of 1829 in Åbo, it was decided that the university should also be moved, renaming it the Imperial Alexander University of Finland after Tsar Alexander I.
In 1831 the Governorate of Nyland-Tavastehus was divided into the Governorate of Nyland (Нюландская губерния, Nylands län, Uudenmaan lääni) and the Governorate of Tavastehus (Тавастгусская губерния, Tavastehus län, Hämeen lääni).