The Battle of Guningtou (simplified Chinese: 古宁頭之役; traditional Chinese: 古寧頭之役; pinyin: Gǔníngtóu zhī Yì), also known as the Battle of Kinmen (simplified Chinese: 金门战役; traditional Chinese: 金門戰役; pinyin: Jīnmén Zhànyì), was a battle fought over Kinmen (Quemoy) in the Taiwan Strait during the Chinese Civil War in 1949. The failure of the Communists to take the island left it in the hands of the Kuomintang (Nationalists) and crushed their chances of taking Taiwan to defeat the Nationalists completely in the war.

Following establishment of the People's Republic of China on October 1, 1949, the government of the Republic of China under Chiang Kai-shek began withdrawing its forces from mainland China to Taiwan. However, ROC garrisons remained stationed on the islands of Quemoy and Matsu, located off the coast in Fujian Province. Commanders of the PRC People's Liberation Army believed that Quemoy and Matsu had to be taken before a final assault on Taiwan. The PLA planned to attack Quemoy by launching a first attack with 9,000 troops to establish a beachhead, before landing a second force of roughly 10,000 on Greater Quemoy Island, expecting to take the entire island in three days from an ROC garrison not expected to be larger than two divisions. Expecting that a PLA attack was imminent, ROC commanders ordered the immediate construction of various fortifications. By October, ROC troops had laid 7455 landmines, and constructed roughly 200 earthen bunkers on the shores of Quemoy, as well as several anti-amphibious landing beach obstacles. The ROC garrison on Quemoy was also reinforced with more armor, troops and supplies.