Bezprym (Old Polish: Bezprzym [ˈbɛspʂɨm]; c. 986–1032) was the duke of Poland from 1031 until his death. He was the eldest son of the Polish king Bolesław the Brave, but was deprived of the succession by his father, who around 1001 sent him to Italy in order to become a monk at one of Saint Romuald's hermitages in Ravenna.

Expelled by his half-brother Mieszko II Lambert after the death of their father, Bezprym became ruler of large areas of Poland in 1031 following a simultaneous attack by German and Kievan forces and Mieszko II's escape to Bohemia. His reign was short-lived and, according to some sources, extremely cruel. He was murdered in 1032 and Mieszko II returned to the throne of Poland. It is speculated that a pagan reaction began during his short reign.

In primary sources Bezprym appears as: Besprim (Thietmar's Chronicle), Besfrim (Annalista Saxo), or Bezbriem (Chronicles of Hildesheim and Annales Altahenses). This name was not used among the Polish nobility but was known in Bohemian sources, where it appears as: Bezprim, Bezprem, or Bezperem. According to one of the hypotheses the name is of pure West Slavic origin, and was probably originally pronounced as Bezprzem or Bezprzym. Due to tradition and the impossibility of determining the correct version of the name, Bezprym remains the form used, although, according to K. Jasiński, it probably requires modifications. This name meant literally "stubborn", "self-confident, not willing to retreat". The name of the Hungarian city of Veszprém is considered to be derived from the same West Slavic name.

Older historiography frequently combined the figures of Bolesław the Brave's sons Otto and Bezprym. Marian Gumowski also suggested, on the basis of numismatic research, that this "combined" prince could have governed the Duchy of Bohemia in 1003. These theories are based on the chronicle of Wipo of Burgundy, who described only one brother of Mieszko II, Otto. Modern historians assume, however, that Bezprym did exist, and that the chronicler erroneously combined Otto and Bezprym into one person.^{[citation needed]}

Bezprym was the only child of Bolesław the Brave born from his second marriage with an unknown Hungarian princess who, in older literature, was identified as Judith, daughter of the Hungarian ruler Géza. Though opinions vary about the actual identity of Bolesław I 's second wife, there are a number of researchers who still support the hypothesis that she was a daughter of Géza. Soon after his birth, the marriage of his parents ended, probably because of the deterioration in political relations between Poland and Hungary. Bezprym's mother was repudiated and sent away, although she probably remained in Poland and died soon afterwards.

Shortly after his divorce, Bolesław I married Emnilda, who bore him five children. The eldest son of this union, the future Mieszko II Lambert, was born in 990.

Little is known about Bezprym's youthful years, in contrast with his half-brother Mieszko II, whose youth was fully described in several contemporary sources. This probably showed that his father disliked him and considered Mieszko II as his successor since his birth, which was confirmed by Bolesław I's later political activity.

Bezprym was then destined to a church career, a fact that was demonstrated in the Vita of St. Romuald, a hermit from Ravenna. There it was stated that in one of the hermitages resided a son of a Polish Duke, who in 1001 gave him a horse. According to modern historians, this Polish prince could only be Bezprym. However, in earlier historiography, it was theorised that the Polish prince who lived in the hermitage of Ravenna was Lambert, son of Mieszko I, or an unknown son of Bolesław I from his first marriage with the daughter of Rikdag, Margrave of Meissen.