Prince Semyon Yurievich of Halshany (Lithuanian: Simonas Juravičius Alšėniškis; died in 1505 or 1506) was a noble from the Olshanski family in the Grand Duchy of Lithuania.

[2] In 1495, sons of Khan Meñli I Giray invaded Volhynia and Olshanski successfully defended the besieged Korets.

[3] When his son-in-law[1] Konstanty Ostrogski was captured in the Battle of Vedrosha in July 1500, Olshanski became the Great Hetman (commander of the army) of the Grand Duchy of Lithuania.

[2] Grand Duke brokered alliances with the Livonian Order and Great Horde, but the Lithuanian army did not organize more active defense and Olshanski was replaced by Stanislovas Kęsgaila in 1501 or 1502.

[1][3] In 1502, Olshanski returned to Volhynia and once again organized defense against the Crimean Khanate that attacked Babruysk, Turov, and Brest.