Bolesław of Oleśnica (Polish: Bolesław oleśnicki; c. 1295 – before 23 April 1321), was a Duke of Żagań, Ścinawa, etc., during 1309-1312 (with his brothers as co-rulers), Duke of Oleśnica, Namysłów, Gniezno and Kalisz during 1312-1313 (with his brother as co-ruler), Duke of Gniezno during 1313-1314 (alone) and Duke of Oleśnica since 1313 until his death (alone).
He was the third son of Henry III (I), Duke of Głogów, by his wife Matilda, daughter of Albert I, Duke of Brunswick-Lüneburg.
At the time of his father's death in 1309, Bolesław succeeded him as ruler of all his lands together with his brothers as co-rulers; however, because he was a minor, was placed under the care of his mother until his majority in 1312. Despite he was legally a minor, he was present with his older brothers Henry IV the Faithful and Konrad I in their negotiations in Berlin, where on 3 March 1310, they solemnly renounced to their rights over Gdańsk Pomerania to Brandenburg in exchange to a monetary compensation (due to the insolvency of the princes of Głogów, they were forced to pledge to the House of Ascania the towns of Krosno Odrzańskie and Żagań, who were only recovered in 1319.
On 29 February 1312 was made first division of the Duchy: Bolesław and Konrad received the Duchies of Gniezno-Kalisz and Oleśnica-Namysłów as a co-rulers, but one year later, in 1313, they decided to divide their domains: Bolesław obtained Oleśnica and Gniezno as a sole ruler.