Przemysław of Toszek (Polish: Przemysław Toszecki) (1425 – December 1484) was a Duke of Oświęcim during 1434–1445 (with his brothers as co-rulers) and Duke of Toszek since 1445 until his death.
He was the second son of Duke Casimir I of Oświęcim by his first wife Anna, daughter of Duke Henry VIII of Żagań.
After the death of his father in 1434, Przemysław found himself under the care of his older brother Wenceslaus I. In 1441 Wenceslaus I succumbing to the pressures of the Polish King and undertook to convince his younger brothers, Przemysław and Jan IV to paid homage to the Polish Kingdom, once they reached adulthood.
The formal division of the Duchy was made on 19 January 1445. Przemysław received the least significant part of the Duchy, the town of Toszek. His first decision as an independent ruler was caught up in conflict with the Bishop of Kraków, Zbigniew Oleśnicki, who purchased Siewierz from the Dukes of Cieszyn. The agreement signed between both parties on 18 February 1447 in Kraków, was short-lived: on 6 October 1450 Przemysław attack with his troops the Bishop's castle in Siewierz.
In 1452 Przemysław supported his younger brother Jan IV in his fight against the Polish King Casimir IV. Soon the brothers's troops were defeated and they were prompted to issue a document (7 March 1453), in which Przemysław took all the responsibility for the war, declared the freedom for all the prisoners, and paid 2,000 fines as a compensation. However, despite the truce concluded, however, Przemysław continue his attacks and forbidden the Polish merchants to enter in his domains. The definitive settlement between the Dukes and Poland took place in Gliwice soon after; under the terms of this treaty, Przemysław consent the sale of the Duchy of Oświęcim to Poland.