Ren Bishi (Chinese: 任弼时; pinyin: Rén Bìshí; Wade–Giles: Jen Pi-shih; 30 April 1904 – 27 October 1950) was a military and political leader in the early Chinese Communist Party (CCP).

In the early 1930s, Ren commanded the Fifth Red Army and was a central figure in the Hunan-Jiangxi Soviet, but he was forced to abandon his base after being pressured by Chiang Kai-shek's Fifth Encirclement Campaigns. In October 1934 Ren and his surviving troops joined the forces of He Long, who had set up a base in Guizhou. In the command structure of the new Second Front Army, He became the military commander and Ren served as its political commissar. Under threat from advancing Kuomintang troops, Ren and He were forced to retreat and went on to participate in the Long March in 1935. During the Second Sino-Japanese War, Ren was the representative of the CCP at the Communist International and the Secretary of the Central Committee of the Chinese Communist Party.

Ren was considered a rising figure within the CCP until his death at the age of 46. He was the fifth most senior party member of the 7th Politburo of the Chinese Communist Party before his death.

Ren Bishi was born in rural Hunan to a teacher's family. He entered Hunan First Normal University in 1915 and collaborated with Mao Zedong to set up the Russian Research Center at the school in 1920. In the same year, he also joined the youth wing of the soon-to-be Chinese Communist Party in Shanghai. In May 1921, Ren and five others - including Liu Shaoqi and Xiao Jinguang - embarked on a chartered trip to the Soviet Union, going around Nagasaki, Vladivostok and the White movement blockade. Arriving in August 1921, the six of them entered the Communist University of the Toilers of the East. Ren joined the Chinese Communist Party in 1922 and replaced Qu Qiubai as the translator of the history of Western revolutionary movements. After completing his studies on 23 July 1924, he arrived in Shanghai in August 1924 after a train ride through Siberia and a chartered boat from Vladivostok. Under the orders of the Party, Ren was appointed to be a lecturer of the Russian language at Shanghai University. He was appointed to the Zhejiang and Anhui District Committee in 1924 and was responsible for publications such as China Youth, Mission Journal and Friends of Civilians.

In January 1925, Ren attended the Socialist Youth League of China's Third National People's Congress as the praesidium and changed the organization's name from "Socialist Youth League" to the "Chinese Communist Youth League". With Zhang Tailei being posted elsewhere in May 1925, Ren was appointed as the First Secretary of the Communist Youth League, in charge of leading the May Thirtieth movement. Despite the failure of the movement, Ren was able to consolidate and utilise the Youth League to vastly expand its membership soon after. In early April 1926, he married Chen Congying in Shanghai. Ren left for Moscow to attend the Communist Youth International Executive Committee Sixth Plenum in October and stayed in the Soviet Union until March the following year.

Following the 1927 White Terror, Ren was elected to become a member of the Central Committee while retaining his secretariat in the Communist Youth League. With the end of the First-United Front Ren sided with Mao Zedong against Chen Duxiu in August 1927 to support the idea of initiating a peasant-based revolution in China. Soon after, Ren was able to gain temporary membership of the Politburo.

On 15 October 1928, Ren was arrested by the local warlord in Nanling County, Anhui Province while attempting to attend a meeting by the Communist Youth League. Although Ren was released by the end of 1928, his son caught pneumonia and died.

In January 1929, he was appointed Minister of the CCP Central Committee and head of propaganda in the Jiangxi Soviet. On 13 August, he was made the temporary secretary of the Jiangxi Soviet, tasked to set up Today News, Education Week and Shanghai Daily. He was detained again on 17 November when attending a municipal meeting organized by the CCP. Even under electrocution and torture, Ren did not provide any confession to the police. As a response to his detainment, Zhou Enlai acted as the negotiator and was able to secure a prison term for Ren and even managed to reduce the term to secure his release by 25 December 1929. In April and September, he was appointed as the party secretary in Hubei and Wuhan. In the same year, he was recalled to Shanghai following the failure of the uprising initiated by Li Lisan in Nanjing.