Abbas Mirza (Persian: عباس میرزا; August 26, 1789 – October 25, 1833) was a Qajar crown prince of Iran. He developed a reputation as a military commander during the Russo-Persian War of 1804–1813 and the Russo-Persian War of 1826–1828, as well as through the Ottoman–Persian War of 1821–1823. He is furthermore noted as an early modernizer of Persia's armed forces and institutions, and for his death before his father, Fath Ali Shah.

Abbas was an intelligent prince, possessed some literary taste, and is noteworthy on account of the comparative simplicity of his life.

With Abbas Mirza as the military commander of the Persian forces, Iran lost all of its territories in the Caucasus comprising the South Caucasus and parts of the North Caucasus (Dagestan) to Russia in conformity with the 1813 Treaty of Gulistan and the 1828 Treaty of Turkmenchay, following the outcomes of the 1804–1813 and 1826–1828 wars.