The 4th Infantry Division was a military formation of the Korean People's Army during the 20th Century.

The division's authorized strength was 10,381 officers and men, with most of its fighting power concentrated in the 2,590-man infantry regiments.

[1] Commanded by Maj. Gen. Lee Kwon Mu, a veteran of the Chinese Communist Forces and former NKPA chief of staff, and composed largely of ethnic Koreans who had fought in the Chinese Civil War, the division had played a major role in the capture of the South Korean capital, Seoul.

By the time it reached the Naktong River, its strength was estimated by the Eighth Army Intelligence Section to be no more than 8,000 men, and its artillery component had been reduced to only twelve guns.

Nevertheless, the 4th Division still held the initiative and began immediate preparations to launch an assault across the river.