Li Zongren or Li Tsung-jen (13 August 1890 – 30 January 1969) was a prominent Guangxi warlord and Kuomintang (KMT) military commander during the Northern Expedition, Second Sino-Japanese War and Chinese Civil War. He served as vice-president and acting President of the Republic of China under the 1947 Constitution.

In 1937 full-scale war between Japan and China broke out, beginning the Second Sino-Japanese War (1937–45). Chiang Kai-shek attempted to make use of Li's military experience by promoting him to be the director of the KMT Fifth War Zone. Li's first action against the Japanese came in the 1938 Battle of Taierzhuang, after the Communist Zhou Enlai (who was aiding the Nationalists as part of the United Front) recognized Li as the most capable Nationalist general available and used his influence to have Li appointed overall commander, despite Chiang's reservations about Li's loyalty. Under Li's command the defense of Tai'erzhuang was a major victory for the Chinese, killing 20,000–30,000 Japanese soldiers and capturing a large amount of supplies and equipment. The victory was principally credited to Li's planning and use of tactics, luring the Japanese into a trap and then annihilating them. The battle of Taierzhuang was one of the first major Chinese victories in the war against Japan, proving that with good weapons and inspired leadership Chinese armies could hold their own. Li also participated in the Battle of Xuzhou, Battle of Wuhan, Battle of Suixian-Zaoyang, 1939–40 Winter Offensive, Battle of Zaoyang-Yichang, Central Hopei Operation, and Battle of South Henan.

From 1943 to 1945 Li was made Director of the Generalissimo's Headquarters. This was a virtual and unwanted retirement from active command after his earlier successes. Li spent the last years of the war grumbling about his enforced inactivity.

On 28 April 1948 Li was elected by the National Assembly as the vice-president, five days after his political opponent Chiang Kai-shek became the president (Chiang had opposed Li's appointment, supporting Sun Fo's candidacy instead). Chiang resigned the next year, on 21 January 1949, as a response to several serious Chinese Communist victories in northern China, and Li became the acting president the next day.