Yishan (13 June 1790 – 30 June 1878), was a Manchu lesser noble and official of the Qing dynasty. He is best known for his failure to defend Guangzhou (Canton) from British forces during the First Opium War, and for signing the treaties of Kulja and Aigun with the Russian Empire in 1851 and 1858 respectively.

In 1841, when the First Opium War broke out, the Daoguang Emperor dismissed Qishan from his position as Imperial Commissioner overseeing military affairs in Guangdong Province, and appointed Yishan as "Jingni General" to replace Qishan. Yishan distrusted the local people in Guangdong Province and strengthened defences against them instead of against the British. He recruited inexperienced fresh recruits from Fujian Province to serve in the Qing military instead of seasoned soldiers. Besides, he also spent his time partying with the officers. On 21 May 1841, Yishan ordered his troops to launch a sneak attack on the British at night, but the attack failed. The British captured all the artillery positions outside Guangzhou. The Qing forces retreated into the city and did not dare to engage the British. Chaos broke out in Guangzhou when the volunteer militias from Nanhai and Hunan started fighting over supplies. On 26 May, Yishan surrendered to the British and signed the Treaty of Guangzhou with Charles Elliot. During his time in Canton, Yishan repeatedly sent lies and misinformation to the Daoguang emperor, making it seem that the Qing forces were stronger than the British.