The Province of Silesia (German: Provinz Schlesien; Polish: Prowincja Śląska; Silesian: Prowincyjŏ Ślōnskŏ) was a province of Prussia from 1815 to 1919. The Silesia region was part of the Prussian realm since 1742 and established as an official province in 1815, then became part of the German Empire in 1871. In 1919, as part of the Free State of Prussia within Weimar Germany, Silesia was divided into the provinces of Upper Silesia and Lower Silesia. Silesia was reunified briefly from 1 April 1938 to 27 January 1941 as a province of Nazi Germany before being divided back into Upper Silesia and Lower Silesia.

Breslau (present-day Wrocław, Poland) was the provincial capital.

The territory on both sides of the Oder river formed the southeastern part of the Prussian kingdom. It comprised the bulk of the former Bohemian crown land of Upper and Lower Silesia as well as the adjacent County of Kladsko, which the Prussian King Frederick the Great had all conquered from the Austrian Habsburg monarchy under Empress Maria Theresa in the 18th century Silesian Wars. It included the northeastern part of Upper Lusatia around Görlitz and Lauban (Lubań), ceded to Prussia by the Kingdom of Saxony according to the resolutions of the Congress of Vienna in 1815.

The province bordered on the Prussian heartland of Brandenburg (including the newly acquired lands of Lower Lusatia) in the northwest, and on the Grand Duchy of Posen (Province of Posen from 1848) in the north, i.e. the Greater Polish lands that before the 18th century Partitions of Poland had belonged to the Polish–Lithuanian Commonwealth.

In the northeast, Upper Silesia bordered on Congress Poland, i.e. the Kingdom of Poland which had been reconstituted from the Duchy of Warsaw and was made up of former parts of the Prussian and Austrian partitions. Congress Poland was in a personal union with the Russian Empire until 1867 when it was formally integrated as the Vistula Land.

In the east lay the Austrian share, the Lesser Polish Kingdom of Galicia and Lodomeria with the Free City of Kraków until 1846, and in the south the remaining Bohemian crown lands of Austrian Silesia, Moravia and Bohemia proper. The incorporated Upper Lusatian strip of land in the west touched the remaining territory of the Saxon kingdom and in the furthest west the Prussian Province of Saxony.

The coronation of Maria Theresa as queen regnant of the Kingdom of Bohemia immediately triggered an invasion of the region of Silesia by King Frederick the Great of Prussia, thereby starting the War of the Austrian Succession (1740–1748). By the end of the First Silesian War in 1742, the Prussian forces had conquered almost all of the Habsburg crown land in Silesia. The conquest marked the beginning of the era of Prussian Silesia.

According to the peace treaties of Breslau and Berlin, only some smaller parts in the extreme southeast, like the Duchy of Cieszyn as well as the southern parts of the duchies of Troppau and Nysa, remained possessions of the Habsburg monarchy as Austrian Silesia. Attempts by Maria Theresa to regain the crown land in the Second Silesian War (1744–1745) failed and she ultimately had to relinquish her claims over Silesia by the Treaty of Dresden.