The siege of Changchun was a military blockade undertaken by the People's Liberation Army against Changchun between May and October 1948, the largest city in Manchuria at the time, and one of the headquarters of the Republic of China Army in Northeast China. It was one of the longest campaigns in the Liaoshen Campaign of the Chinese Civil War.

For the Nationalist government, the fall of Changchun made it clear that the KMT was no longer able to hold on to Manchuria. The city of Shenyang and the rest of Manchuria were quickly defeated by the PLA. The siege warfares employed by the CCP throughout the campaigns in the Northeast were highly successful, which reduced a significant number of KMT troops and altered the balance of power.