The siege of Kandahar began when Nader Shah's Afsharid army invaded southern Afghanistan to topple the last Hotaki stronghold of Loy Kandahar, which was held by Hussain Hotaki. It took place in the Old Kandahar area of the modern city of Kandahar in Afghanistan and lasted until March 24, 1738, when the Hotaki Afghans were defeated by the Persian army.

Nader Shah Afshar was the founder of the Afsharid dynasty of Iran and one of the most powerful rulers in Iranian history, ruling as shah of Iran (Persia) from 1736 to 1747, when he was assassinated during a rebellion. He fought numerous campaigns throughout the Middle East, the Caucasus, Central Asia, and South Asia, such as the battles of Herat, Mihmandust, Murche-Khort, Kirkuk, Yeghevārd, Khyber Pass, Karnal, and Kars. Because of his military genius, some historians have described him as the Napoleon of Persia, the Sword of Persia, or the Second Alexander. Nader belonged to the Turkoman Afshars, one of the seven Qizilbash tribes that helped the Safavid dynasty establish their power in Iran.