Communist Party of Western Ukraine (Ukrainian: Комуністична партія Західної України) was a political party in eastern interbellum Poland. Until 1923 it was known as the Communist Party of Eastern Galicia.
Young Communist League of Western Ukraine was the youth league of the party.
The party was more influential during the NEP era in Soviet Russia resp. Soviet Union and the Ukrainization in Soviet Ukraine. Its influence faded away in 1930s due to Stalin's terror regime in the USSR and execution of his policies in Ukraine by Lazar Kaganovich. At times, the Communist Party of Western Ukraine was split into different wings, pro-Soviet and more independent. In 1927 the majority of the Central Committee of the CPWU supported the 'nationalist' faction of Alexander Shumsky in the CPU(B). As a consequence, Kaganovich who was the general secretary of the CPU(B), accused the Western Ukrainian communists of treason. The CPWU split into majority 'nationalist' faction and a pro-Kaganovich minority. On 18 February 1928 the majority-CPWU led by Ivan Krilyk and Roman Turyansky was expelled from Comintern. By the end of 1928, the CPWU (majority) disbanded itself and its leaders who expressed regrets because of their 'errors' went to the USSR, where they were later repressed. The pro-Soviet minority continued as CPWU.
In 1938 the Executive committee of Comintern decided to disband the Communist Party of Poland, together with the Communist parties of Western Belarus and Western Ukraine. This decision was sparked by accusations that the leadership of those parties had been taken over by 'fascist agents'. Almost all the members of the CPWU who were in the USSR at the time, were repressed. Many activists who remained in Western Ukraine (Poland) were repressed later in 1939, after the Soviet invasion of Poland.